हिंदी

R.D. Sharma solutions for Mathematics [English] Class 8 chapter 6 - Algebraic Expressions and Identities [Latest edition]

Advertisements

Chapters

R.D. Sharma solutions for Mathematics [English] Class 8 chapter 6 - Algebraic Expressions and Identities - Shaalaa.com
Advertisements

Solutions for Chapter 6: Algebraic Expressions and Identities

Below listed, you can find solutions for Chapter 6 of CBSE R.D. Sharma for Mathematics [English] Class 8.


Exercise 6.1Exercise 6.2Exercise 6.3Exercise 6.4Exercise 6.5Exercise 6.6Exercise 6.7
Exercise 6.1 [Page 2]

R.D. Sharma solutions for Mathematics [English] Class 8 6 Algebraic Expressions and Identities Exercise 6.1 [Page 2]

1.1Page 2

Identify the term, their coefficients for the following expression:

 7x2yz − 5xy

1.2Page 2

Identify the term, their coefficients for the following expression:

 x2 + x + 1

1.3Page 2

Identify the term, their coefficients for the following expression:

 3x2y2 − 5x2y2z2 + z2

1.4Page 2

Identify the term, their coefficients for the following expression:

9 − ab + bc − ca

1.5Page 2

Identify the term, their coefficients for the following expression:

\[\frac{a}{2} + \frac{b}{2} - ab\]

1.6Page 2

Identify the term, their coefficients for the following expression:

0.2x − 0.3xy + 0.5y

2.01Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

x + y

2.02Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

 1000

2.03Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

x + x2 + x3 + 4y4

2.04Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

 7 + a + 5b

2.05Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

2b − 3b2

2.06Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

 2y − 3y2 + 4y3

2.07Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

5x − 4y + 3x

2.08Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

 4a − 15a2

2.09Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

xy + yz + zt + tx

2.1Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

 pqr

2.11Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

p2q + pq2

2.12Page 2

Classify the following polynomial as monomial, binomial, trinomial. Which polynomial do not fit in any category?

2p + 2q

Exercise 6.2 [Pages 5 - 6]

R.D. Sharma solutions for Mathematics [English] Class 8 6 Algebraic Expressions and Identities Exercise 6.2 [Pages 5 - 6]

1.1Page 5

Add the following algebraic expression:

3a2b, − 4a2b, 9a2b

1.2Page 5

Add the following algebraic expression:

\[\frac{2}{3}a, \frac{3}{5}a, - \frac{6}{5}a\]

1.3Page 5

Add the following algebraic expression:

 4xy2 − 7x2y, 12x2y − 6xy2, − 3x2y +5xy2

1.4Page 5

Add the following algebraic expression:

\[\frac{3}{2}a - \frac{5}{4}b + \frac{2}{5}c, \frac{2}{3}a - \frac{7}{2}b + \frac{7}{2}c, \frac{5}{3}a + \frac{5}{2}b - \frac{5}{4}c\]

1.5Page 5

Add the following algebraic expression:

\[\frac{11}{2}xy + \frac{12}{5}y + \frac{13}{7}x, - \frac{11}{2}y - \frac{12}{5}x - \frac{13}{7}xy\]

1.6Page 5

Add the following algebraic expression: \[\frac{7}{2} x^3 - \frac{1}{2} x^2 + \frac{5}{3}, \frac{3}{2} x^3 + \frac{7}{4} x^2 - x + \frac{1}{3}, \frac{3}{2} x^2 - \frac{5}{2}x - 2\]

2.1Page 5

Subtract:

− 5xy from 12xy

2.2Page 5

Subtract:

2a2 from − 7a2

2.3Page 5

Subtract:

2a − b from 3a − 5b

2.4Page 5

Subtract:

2x3 − 4x2 + 3x + 5 from 4x3 + x2 + x + 6

2.5Page 5

Subtract:

\[\frac{2}{3} y^3 - \frac{2}{7} y^2 - 5 \text { from  }\frac{1}{3} y^3 + \frac{5}{7} y^2 + y - 2\]

2.6Page 5

Subtract: 

\[\frac{3}{2}x - \frac{5}{4}y - \frac{7}{2}z \text { from }\frac{2}{3}x + \frac{3}{2}y - \frac{4}{3}z\]

2.7Page 5

Subtract: 

\[x^2 y - \frac{4}{5}x y^2 + \frac{4}{3}xy \text { from } \frac{2}{3} x^2 y + \frac{3}{2}x y^2 - \frac{1}{3}xy\]

2.8Page 5

Subtract: 

\[\frac{ab}{7} - \frac{35}{3}bc + \frac{6}{5}ac \text { from } \frac{3}{5}bc - \frac{4}{5}ac\]

3.1Page 5

Take away:

\[\frac{6}{5} x^2 - \frac{4}{5} x^3 + \frac{5}{6} + \frac{3}{2}x \text { from  }\frac{x^3}{3} - \frac{5}{2} x^2 + \frac{3}{5}x + \frac{1}{4}\]

3.2Page 5

Take away:

\[\frac{5 a^2}{2} + \frac{3 a^3}{2} + \frac{a}{3} - \frac{6}{5} \text { from } \frac{1}{3} a^3 - \frac{3}{4} a^2 - \frac{5}{2}\]

3.3Page 5

Take away: 

\[\frac{7}{4} x^3 + \frac{3}{5} x^2 + \frac{1}{2}x + \frac{9}{2}\text {  from } \frac{7}{2} - \frac{x}{3} - \frac{x^2}{5}\]

3.4Page 5

Take away: 

\[\frac{y^3}{3} + \frac{7}{3} y^2 + \frac{1}{2}y + \frac{1}{2} \text { from } \frac{1}{3} - \frac{5}{3} y^2\]

3.5Page 5

Take away: 

\[\frac{2}{3}ac - \frac{5}{7}ab + \frac{2}{3}bc\text { from } \frac{3}{2}ab - \frac{7}{4}ac - \frac{5}{6}bc\]

4Page 6

Subtract 3x − 4y − 7z from the sum of x − 3y + 2z and − 4x + 9y − 11z.

5Page 6

Subtract the sum of 3l − 4m − 7n2 and 2l + 3m − 4n2 from the sum of 9l + 2m − 3n2 and − 3l + m + 4n2 .....

6Page 6

Subtract the sum of 2x − x2 + 5 and − 4x − 3 + 7x2 from 5.

7.1Page 6

Simplify the following:

 x2 − 3x + 5 −  \[\frac{1}{2}\] (3x2 − 5x + 7)

7.2Page 6

Simplify the following:

 [5 − 3x + 2y − (2x − y)] − (3x − 7y + 9)

7.3Page 6

Simplify the following:

\[\frac{11}{2} x^2 y - \frac{9}{4}x y^2 + \frac{1}{4}xy - \frac{1}{14} y^2 x + \frac{1}{15}y x^2 + \frac{1}{2}xy\]

7.4Page 6

Simplify the following:

\[\left( \frac{1}{3} y^2 - \frac{4}{7}y + 11 \right) - \left( \frac{1}{7}y - 3 + 2 y^2 \right) - \left( \frac{2}{7}y - \frac{2}{3} y^2 + 2 \right)\]

7.5Page 6

Simplify the following: \[- \frac{1}{2} a^2 b^2 c + \frac{1}{3}a b^2 c - \frac{1}{4}ab c^2 - \frac{1}{5}c b^2 a^2 + \frac{1}{6}c b^2 a - \frac{1}{7} c^2 ab + \frac{1}{8}c a^2 b .\]

Exercise 6.3 [Pages 13 - 14]

R.D. Sharma solutions for Mathematics [English] Class 8 6 Algebraic Expressions and Identities Exercise 6.3 [Pages 13 - 14]

1Page 13

Find each of the following product:
5x2 × 4x3

2Page 13

Find each of the following product:
−3a2 × 4b4

3Page 13

Find each of the following product:
(−5xy) × (−3x2yz)

4Page 13

Find each of the following product: 

\[\frac{1}{4}xy \times \frac{2}{3} x^2 y z^2\]

5Page 14

Find each of the following product: 

\[\left( - \frac{7}{5}x y^2 z \right) \times \left( \frac{13}{3} x^2 y z^2 \right)\]

6Page 14

Find each of the following product: \[\left( \frac{- 24}{25} x^3 z \right) \times \left( - \frac{15}{16}x z^2 y \right)\]

7Page 14

Find each of the following product:

\[\left( - \frac{1}{27} a^2 b^2 \right) \times \left( \frac{9}{2} a^3 b^2 c^2 \right)\]

8Page 14

Find each of the following product: \[( - 7xy) \times \left( \frac{1}{4} x^2 yz \right)\]

9Page 14

Find each of the following product:
(7ab) × (−5ab2c) × (6abc2)

10Page 14

Find each of the following product:
(−5a) × (−10a2) × (−2a3)

11Page 14

Find each of the following product:
(−4x2) × (−6xy2) × (−3yz2)

12Page 14

Find each of the following product:

\[\left( - \frac{2}{7} a^4 \right) \times \left( - \frac{3}{4} a^2 b \right) \times \left( - \frac{14}{5} b^2 \right)\]

13Page 14

Find each of the following product: \[\left( \frac{7}{9}a b^2 \right) \times \left( \frac{15}{7}a c^2 b \right) \times \left( - \frac{3}{5} a^2 c \right)\]

14Page 14

Find each of the following product: \[\left( \frac{4}{3} u^2 vw \right) \times \left( - 5uv w^2 \right) \times \left( \frac{1}{3} v^2 wu \right)\]

15Page 14

Find each of the following product:

\[\left( 0 . 5x \right) \times \left( \frac{1}{3}x y^2 z^4 \right) \times \left( 24 x^2 yz \right)\]

16Page 14

Find each of the following product: \[\left( \frac{4}{3}p q^2 \right) \times \left( - \frac{1}{4} p^2 r \right) \times \left( 16 p^2 q^2 r^2 \right)\]

17Page 14

Find each of the following product:
(2.3xy) × (0.1x) × (0.16)

18Page 14

Express each of the following product as a monomials and verify the result in each case for x = 1:
(3x) × (4x) × (−5x)

19Page 14

Express each of the following product as a monomials and verify the result in each case for x = 1:
(4x2) × (−3x) × \[\left( \frac{4}{5} x^3 \right)\]

20Page 14

Express each of the following product as a monomials and verify the result in each case for x = 1:
(5x4) × (x2)3 × (2x)2

21Page 14

Express each of the following product as a monomials and verify the result in each case for x = 1:
(x2)3 × (2x) × (−4x) × (5)

22Page 14

Write down the product of −8x2y6 and −20xy. Verify the product for x = 2.5, y = 1.

23Page 14

Evaluate (3.2x6y3) × (2.1x2y2) when x = 1 and y = 0.5.

24Page 14

Find the value of (5x6) × (−1.5x2y3) × (−12xy2) when x = 1, y = 0.5.

25Page 14

Evaluate (2.3a5b2) × (1.2a2b2) when a = 1 and b = 0.5.

26Page 14

Evaluate (−8x2y6) × (−20xy) for x = 2.5 and y = 1.

27Page 14

Express each of the following product as a monomials and verify the result for x = 1, y = 2:
(−xy3) × (yx3) × (xy)

28Page 14

Express each of the following product as a monomials and verify the result for x = 1, y = 2: \[\left( \frac{1}{8} x^2 y^4 \right) \times \left( \frac{1}{4} x^4 y^2 \right) \times \left( xy \right) \times 5\]

29Page 14

Express each of the following product as a monomials and verify the result for x = 1, y = 2:

\[\left( \frac{2}{5} a^2 b \right) \times \left( - 15 b^2 ac \right) \times \left( - \frac{1}{2} c^2 \right)\]
30Page 14

Express each of the following product as a monomials and verify the result for x = 1, y = 2: \[\left( - \frac{4}{7} a^2 b \right) \times \left( - \frac{2}{3} b^2 c \right) \times \left( - \frac{7}{6} c^2 a \right)\]

31Page 14

Express each of the following product as a monomials and verify the result for x = 1, y = 2:

\[\left( \frac{4}{9}ab c^3 \right) \times \left( - \frac{27}{5} a^3 b^2 \right) \times \left( - 8 b^3 c \right)\]

 
32Page 14

Evaluate each of the following when x = 2, y = −1.

\[(2xy) \times \left( \frac{x^2 y}{4} \right) \times \left( x^2 \right) \times \left( y^2 \right)\]

33Page 14

Evaluate each of the following when x = 2, y = −1. 

\[\left( \frac{3}{5} x^2 y \right) \times \left( - \frac{15}{4}x y^2 \right) \times \left( \frac{7}{9} x^2 y^2 \right)\]

Exercise 6.4 [Page 21]

R.D. Sharma solutions for Mathematics [English] Class 8 6 Algebraic Expressions and Identities Exercise 6.4 [Page 21]

1Page 21

Find the following product:
2a3(3a + 5b)

2Page 21

Find the following product:
−11a(3a + 2b)

3Page 21

Find the following product:
−5a(7a − 2b)

4Page 21

Find the following product:
−11y2(3y + 7)

5Page 21

Find the following product: \[\frac{6x}{5}( x^3 + y^3 )\]

6Page 21

xy(x3 − y3)

7Page 21

Find the following product:
0.1y(0.1x5 + 0.1y)

8Page 21

Find the following product: \[\left( - \frac{7}{4}a b^2 c - \frac{6}{25} a^2 c^2 \right)( - 50 a^2 b^2 c^2 )\]

9Page 21

Find the following product: \[- \frac{8}{27}xyz\left( \frac{3}{2}xy z^2 - \frac{9}{4}x y^2 z^3 \right)\]

10Page 21

Find the following product: \[- \frac{4}{27}xyz\left( \frac{9}{2} x^2 yz - \frac{3}{4}xy z^2 \right)\]

11Page 21

Find the following product:
1.5x(10x2y − 100xy2)

12Page 21

Find the following product:
4.1xy(1.1x − y)

13Page 21

Find the following product:
250.5xy \[\left( xz + \frac{y}{10} \right)\]

14Page 21

Find the following product: \[\frac{7}{5} x^2 y\left( \frac{3}{5}x y^2 + \frac{2}{5}x \right)\]

15Page 21

Find the following product: \[\frac{4}{3}a( a^2 + b^2 - 3 c^2 )\]

16Page 21

Find the product 24x2 (1 − 2x) and evaluate its value for x = 3.

17Page 21

Find the product −3y(xy + y2) and find its value for x = 4 and y = 5.

18Page 21

Multiply \[- \frac{3}{2} x^2 y^3 by (2x - y)\] and verify the answer for x = 1 and y = 2.

19.1Page 21

Multiply the monomial by the binomial and find the value for x = −1, y = 0.25 and z = 0.05: 15y2(2 − 3x)

19.2Page 21

Multiply the monomial by the binomial and find the value for x = −1, y = 0.25 and z = 0.05: −3x(y2 + z2)

19.3Page 21

Multiply the monomial by the binomial and find the value for x = −1, y = 0.25 and z = 0.05: z2(x − y)

19.4Page 21

Multiply the monomial by the binomial and find the value for x = −1, y = 0.25 and z = 0.05:

xz(x2 + y2)

20.01Page 21

Simplify: 2x2(x3 − x) − 3x(x4 + 2x) − 2(x4 − 3x2)

20.02Page 21

Simplify: x3y(x2 − 2x) + 2xy(x3 − x4)

20.03Page 21

Simplify: 3a2 + 2(a + 2) − 3a(2a + 1)

20.04Page 21

Simplify: x(x + 4) + 3x(2x2 − 1) + 4x2 + 4

20.05Page 21

Simplify:  a(b − c) − b(c − a) − c(a − b)

20.06Page 21

Simplify: a(b − c) + b(c − a) + c(a − b)

20.07Page 21

Simplify: 4ab(a − b) − 6a2(b − b2) − 3b2(2a2 − a) + 2ab(b − a)

20.08Page 21

Simplify:  x2(x2 + 1) − x3(x + 1) − x(x3 − x)

20.09Page 21

Simplify:   2a2 + 3a(1 − 2a3) + a(a + 1)

20.1Page 21

Simplify: a2(2a − 1) + 3a + a3 − 8

20.11Page 21

Simplify: \[\frac{3}{2} x^2 ( x^2 - 1) + \frac{1}{4} x^2 ( x^2 + x) - \frac{3}{4}x( x^3 - 1)\]

20.12Page 21

Simplify: a2b(a − b2) + ab2(4ab − 2a2) − a3b(1 − 2b)

20.13Page 21

Simplify:  a2b(a3 − a + 1) − ab(a4 − 2a2 + 2a) − b (a3 − a2 − 1)

Exercise 6.5 [Pages 30 - 31]

R.D. Sharma solutions for Mathematics [English] Class 8 6 Algebraic Expressions and Identities Exercise 6.5 [Pages 30 - 31]

1Page 30

Multiply:
(5x + 3) by (7x + 2)

2Page 30

Multiply:
(2x + 8) by (x − 3)

3Page 30

Multiply:
(7x + y) by (x + 5y)

4Page 30

Multiply:
(a − 1) by (0.1a2 + 3)

5Page 30

Multiply:
(3x2 + y2) by (2x2 + 3y2)

6Page 30

Multiply: \[\left( \frac{3}{5}x + \frac{1}{2}y \right) by \left( \frac{5}{6}x + 4y \right)\]

7Page 31

Multiply:
(x6 − y6) by (x2 + y2)

8Page 31

Multiply:
(x2 + y2) by (3a + 2b)

9Page 31

Multiply:
[−3d + (−7f)] by (5d + f)

10Page 31

Multiply:
(0.8a − 0.5b) by (1.5a − 3b)

11Page 31

Multiply:
(2x2y2 − 5xy2) by (x2 − y2)

12Page 31

Multiply: \[\left( \frac{x}{7} + \frac{x^2}{2} \right)by\left( \frac{2}{5} + \frac{9x}{4} \right)\]

13Page 31

Multiply: \[\left( - \frac{a}{7} + \frac{a^2}{9} \right)by\left( \frac{b}{2} - \frac{b^2}{3} \right)\].

14Page 31

Multiply:
(3x2y − 5xy2) by  \[\left( \frac{1}{5} x^2 + \frac{1}{3} y^2 \right)\].

15Page 31

Multiply:
(2x2 − 1) by (4x3 + 5x2)

16Page 31

(2xy + 3y2) (3y2 − 2)

17Page 31

Find the following product and verify the result for x = − 1, y = − 2:
(3x − 5y) (x + y)

18Page 31

Find the following product and verify the result for x = − 1, y = − 2:
(x2y − 1) (3 − 2x2y)

19Page 31

Find the following product and verify the result for x = − 1, y = − 2: \[\left( \frac{1}{3}x - \frac{y^2}{5} \right)\left( \frac{1}{3}x + \frac{y^2}{5} \right)\]

20Page 31

Simplify:
x2(x + 2y) (x − 3y)

21Page 31

Simplify:

(x2 − 2y2) (x + 4y) x2y2

22Page 31

Simplify:
a2b2(a + 2b)(3a + b)

23Page 31

Simplify:
x2(x − y) y2(x + 2y)

24Page 31

Simplify:
(x3 − 2x2 + 5x − 7)(2x − 3)

25Page 31

Simplify:
(5x + 3)(x − 1)(3x − 2)

26Page 31

Simplify:
(5 − x)(6 − 5x)( 2 − x)

27Page 31

Simplify:
(2x2 + 3x − 5)(3x2 − 5x + 4)

28Page 31

Simplify:
(3x − 2)(2x − 3) + (5x − 3)(x + 1)

29Page 31

Simplify:
(5x − 3)(x + 2) − (2x + 5)(4x − 3)

30Page 31

Simplify:
(3x + 2y)(4x + 3y) − (2x − y)(7x − 3y)

31Page 31

Simplify:
(x2 − 3x + 2)(5x − 2) − (3x2 + 4x − 5)(2x − 1)

32Page 31

Simplify:
(x3 − 2x2 + 3x − 4) (x −1) − (2x − 3)(x2 − x + 1)

Exercise 6.6 [Pages 43 - 44]

R.D. Sharma solutions for Mathematics [English] Class 8 6 Algebraic Expressions and Identities Exercise 6.6 [Pages 43 - 44]

1.01Page 43

Write the following square of binomial as trinomial: (x + 2)2

1.02Page 43

Write the following square of binomial as trinomial:  (8a + 3b)2

1.03Page 43

Write the following square of binomial as trinomial:  (2m + 1)2

1.04Page 43

Write the following square of binomial as trinomial:  \[\left( 9a + \frac{1}{6} \right)^2\]

1.05Page 43

Write the following square of binomial as trinomial: 

\[\left( x + \frac{x^2}{2} \right)^2\]

1.06Page 43

Write the following square of binomial as trinomial:  \[\left( \frac{x}{4} - \frac{y}{3} \right)\]

1.07Page 43

Write the following square of binomial as trinomial:  \[\left( 3x - \frac{1}{3x} \right)^2\]

1.08Page 43

Write the following square of binomial as trinomial:  \[\left( \frac{x}{y} - \frac{y}{x} \right)^2\]

1.09Page 43

Write the following square of binomial as trinomial: \[\left( \frac{3a}{2} - \frac{5b}{4} \right)^2\]

1.1Page 43

Write the following square of binomial as trinomial: (a2b − bc2)2

1.11Page 43

Write the following square of binomial as trinomial:  \[\left( \frac{2a}{3b} + \frac{2b}{3a} \right)^2\]

1.12Page 43

Write the following square of binomial as trinomial:  (x2 − ay)2

2.1Page 43

Find the product of the following binomial: (2x + y)(2x + y)

2.2Page 43

Find the product of the following binomial:  (a + 2b)(a − 2b)

2.3Page 43

Find the product of the following binomial:  (a2 + bc)(a− bc)

2.4Page 43

Find the product of the following binomial: \[\left( \frac{4x}{5} - \frac{3y}{4} \right)\left( \frac{4x}{5} + \frac{3y}{4} \right)\]

2.5Page 43

Find the product of the following binomial: \[\left( 2x + \frac{3}{y} \right)\left( 2x - \frac{3}{y} \right)\]

2.6Page 43

Find the product of the following binomial: (2a3 + b3)(2a3 − b3)

2.7Page 43

Find the product of the following binomial: \[\left( x^4 + \frac{2}{x^2} \right)\left( x^4 - \frac{2}{x^2} \right)\]

2.8Page 43

Find the product of the following binomial: \[\left( x^3 + \frac{1}{x^3} \right)\left( x^3 - \frac{1}{x^3} \right)\]

3.1Page 43

Using the formula for squaring a binomial, evaluate the following:  (102)2

3.2Page 43

Using the formula for squaring a binomial, evaluate the following: (99)2

3.3Page 43

Using the formula for squaring a binomial, evaluate the following:  (1001)2

3.4Page 43

Using the formula for squaring a binomial, evaluate the following:  (999)2

3.5Page 43

Using the formula for squaring a binomial, evaluate the following:  (703)2

4.1Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2: (82)2 − (18)2

4.2Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2: (467)2 − (33)2

4.3Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2: (79)2 − (69)2

4.4Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2: 197 × 203

4.5Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2: 113 × 87

4.6Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2: 95 × 105

4.7Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2: 1.8 × 2.2

4.8Page 43

Simplify the following using the formula: (a − b)(a + b) = a2 − b2:  9.8 × 10.2

5.1Page 43

Simplify the following using the identities: \[\frac{{58}^2 - {42}^2}{16}\]

5.2Page 43

Simplify the following using the identities: 178 × 178 − 22 × 22

5.3Page 43

Simplify the following using the identities: \[\frac{198 \times 198 - 102 \times 102}{96}\]

5.4Page 43

Simplify the following using the identities:  1.73 × 1.73 − 0.27 × 0.27

5.5Page 43

Simplify the following using the identities: \[\frac{8 . 63 \times 8 . 63 - 1 . 37 \times 1 . 37}{0 . 726}\]

6.1Page 43

Find the value of x, if 4x = (52)2 − (48)2.

6.2Page 43

Find the value of x, if 14x = (47)2 − (33)2.

6.3Page 43

Find the value of x, if 5x = (50)2 − (40)2.

7Page 43

If \[x + \frac{1}{x} = 20,\]find the value of \[x^2 + \frac{1}{x^2} .\].

8Page 43

If \[x - \frac{1}{x} = 3,\]  find the values of \[x^2 + \frac{1}{x^2}\] and \[x^4 + \frac{1}{x^4} .\]

9Page 43

If \[x^2 + \frac{1}{x^2} = 18,\]  find the values of \[x + \frac{1}{x} \text { and } x - \frac{1}{x} .\]

10Page 43

If x + y = 4 and xy = 2, find the value of x2 + y2

11Page 43

If x − y = 7 and xy = 9, find the value of x2 + y2

12Page 44

If 3x + 5y = 11 and xy = 2, find the value of 9x2 + 25y2

13.1Page 44

Find the value of the following expression: 16x2 + 24x + 9, when \[x = \frac{7}{4}\]

13.2Page 44

Find the value of the following expression:  64x2 + 81y2 + 144xy, when x = 11 and \[y = \frac{4}{3}\]

13.3Page 44

Find the value of the following expression:  81x2 + 16y2 − 72xy, when \[x = \frac{2}{3}\] and  \[y = \frac{3}{4}\]

14Page 44

If \[x + \frac{1}{x} = 9,\]  find the value of \[x^4 + \frac{1}{x^4} .\]

15Page 44

If \[x + \frac{1}{x} = 12,\]  find the value of \[x - \frac{1}{x} .\]

16Page 44

If 2x + 3y = 14 and 2x − 3y = 2, find the value of xy.
[Hint: Use (2x + 3y)2 − (2x − 3y)2 = 24xy]

17.1Page 44

If x2 + y2 = 29 and xy = 2, find the value of x + y.

17.2Page 44

If x2 + y2 = 29 and xy = 2, find the value of x - y.

17.3Page 44

If x2 + y2 = 29 and xy = 2, find the value of x4 + y4 .

18.1Page 44

What must be added to the following expression to make it a whole square? 

4x2 − 12x + 7

18.2Page 44

What must be added to the following expression to make it a whole square? 

4x2 − 20x + 20

19.1Page 44

Simplify : (x − y)(x + y) (x2 + y2)(x4 + y2)

19.2Page 44

Simplify : (2x − 1)(2x + 1)(4x2 + 1)(16x4 + 1)

19.3Page 44

Simplify : (4m − 8n)2 + (7m + 8n)2

19.4Page 44

Simplify : (2.5p − 1.5q)2 − (1.5p − 2.5q)2

19.5Page 44

Simplify :  (m2 − n2m)2 + 2m3n2

20.1Page 44

Show that:  (3x + 7)2 − 84x = (3x − 7)2

20.2Page 44

Show that:  (9a − 5b)2 + 180ab = (9a + 5b)

20.3Page 44

Show that: \[\left( \frac{4m}{3} - \frac{3n}{4} \right)^2 + 2mn = \frac{16 m^2}{9} + \frac{9 n^2}{16}\]

20.4Page 44

Show that:  (4pq + 3q)2 − (4pq − 3q)2 = 48pq2

20.5Page 44

Show that:  (a − b)(a + b) + (b − c)(b + c) + (c − a)( c + a) = 0

Exercise 6.7 [Page 47]

R.D. Sharma solutions for Mathematics [English] Class 8 6 Algebraic Expressions and Identities Exercise 6.7 [Page 47]

1.01Page 47

Find the following product: (x + 4) (x + 7)

1.02Page 47

Find the following product:  (x − 11) (x + 4)

1.03Page 47

Find the following product: (x + 7) (x − 5)

1.04Page 47

Find the following product: (x − 3) ( x − 2)

1.05Page 47

Find the following product: (y2 − 4) (y2 − 3)

1.06Page 47

Find the following product: \[\left( x + \frac{4}{3} \right)\left( x + \frac{3}{4} \right)\]

1.07Page 47

Find the following product: (3x + 5) (3x + 11)

1.08Page 47

Find the following product:  (2x2 − 3) (2x2 + 5)

1.09Page 47

Find the following product: (z2 + 2) (z2 − 3)

1.1Page 47

Find the following product: (3x − 4y) (2x − 4y)

1.11Page 47

Find the following product:  (3x2 − 4xy) (3x2 − 3xy)

1.12Page 47

Find the following product: \[\left( x + \frac{1}{5} \right)(x + 5)\]

1.13Page 47

Find the following product: \[\left( z + \frac{3}{4} \right)\left( z + \frac{4}{3} \right)\]

1.14Page 47

Find the following product:  (x2 + 4) (x2 + 9)

1.15Page 47

Find the following product: (y2 + 12) (y2 + 6)

1.16Page 47

Find the following product: \[\left( y^2 + \frac{5}{7} \right)\left( y^2 - \frac{14}{5} \right)\]

1.17Page 47

Find the following product:  (p2 + 16) \[\left( p^2 - \frac{1}{4} \right)\]

2.1Page 47

Evaluate the following: 102 × 106

2.2Page 47

Evaluate the following: 109 × 107

2.3Page 47

Evaluate the following: 35 × 37

2.4Page 47

Evaluate the following: 53 × 55

2.5Page 47

Evaluate the following: 103 × 96

2.6Page 47

Evaluate the following: 34 × 36

2.7Page 47

Evaluate the following: 994 × 1006

Solutions for 6: Algebraic Expressions and Identities

Exercise 6.1Exercise 6.2Exercise 6.3Exercise 6.4Exercise 6.5Exercise 6.6Exercise 6.7
R.D. Sharma solutions for Mathematics [English] Class 8 chapter 6 - Algebraic Expressions and Identities - Shaalaa.com

R.D. Sharma solutions for Mathematics [English] Class 8 chapter 6 - Algebraic Expressions and Identities

Shaalaa.com has the CBSE Mathematics Mathematics [English] Class 8 CBSE solutions in a manner that help students grasp basic concepts better and faster. The detailed, step-by-step solutions will help you understand the concepts better and clarify any confusion. R.D. Sharma solutions for Mathematics Mathematics [English] Class 8 CBSE 6 (Algebraic Expressions and Identities) include all questions with answers and detailed explanations. This will clear students' doubts about questions and improve their application skills while preparing for board exams.

Further, we at Shaalaa.com provide such solutions so students can prepare for written exams. R.D. Sharma textbook solutions can be a core help for self-study and provide excellent self-help guidance for students.

Concepts covered in Mathematics [English] Class 8 chapter 6 Algebraic Expressions and Identities are Algebraic Expressions, Terms, Factors and Coefficients of Expression, Addition of Algebraic Expressions, Multiplication of Algebraic Expressions, Multiplying Monomial by Monomials, Multiplying a Monomial by a Binomial, Classification of Terms in Algebra, Subtraction of Algebraic Expressions, Multiplying a Monomial by a Trinomial, Multiplying a Binomial by a Binomial, Multiplying a Binomial by a Trinomial, Concept of Identity, Expansion of (a + b)2 = a2 + 2ab + b2, Expansion of (a - b)2 = a2 - 2ab + b2, Expansion of (a + b)(a - b) = a2-b2, Expansion of (x + a)(x + b).

Using R.D. Sharma Mathematics [English] Class 8 solutions Algebraic Expressions and Identities exercise by students is an easy way to prepare for the exams, as they involve solutions arranged chapter-wise and also page-wise. The questions involved in R.D. Sharma Solutions are essential questions that can be asked in the final exam. Maximum CBSE Mathematics [English] Class 8 students prefer R.D. Sharma Textbook Solutions to score more in exams.

Get the free view of Chapter 6, Algebraic Expressions and Identities Mathematics [English] Class 8 additional questions for Mathematics Mathematics [English] Class 8 CBSE, and you can use Shaalaa.com to keep it handy for your exam preparation.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×