Selina solutions for Mathematics [English] Class 6 chapter 20 - Substitution (Including Use of Brackets as Grouping Symbols) [Latest edition]

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

x + y = .......

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

y − x = ...........

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

`"y"/"x"` = ...........

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

c ÷ b = ...........

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

z ÷ x = ..................

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

y × d = .............

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

d ÷ x = ..................

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

ab + y = ...............

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

a + b + x = ...................

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

b + z − d = ....................

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

a − b + y = ................

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

z − a − b = ................

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

d − a + x = ................

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

xy − bd = ..............

Fill in the blank, when:
x = 3, y = 6, z = 18, a = 2, b = 8, c = 32 and d = 0.

xz + cd = ...................

Find the value of p + 2q + 3r, when p = 1, q = 5 and r = 2

Find the value of 2a + 4b + 5c, when a = 5, b = 10 and c = 20

Find the value of 3a − 2b, when a = 8 and b = 10

Find the value of 5x + 3y − 6z, when x = 3, y = 5 and z = 4

Find the value of 2p − 3q + 4r − 8s, when p = 10, q = 8, r = 6, and s = 2

Find the value of 6m − 2n − 5p − 3q, when m = 20, n = 10, p = 2 and q = 9

Find the value of 4pq × 2r, when p = 5, q = 3 and r = 1/2

Find the value of `"yx"/"z"`, when x = 8, y = 4 and z = 16

Find the value of `("a+b"-"c")/(2"a")`, when a = 5, b = 7 and c = 2

If a = 3, b = 0, c = 2 and d = 1, find the value of 3a + 2b − 6c + 4d

If a = 3, b = 0, c = 2 and d = 1, find the value of 6a − 3b − 4c − 2d

If a = 3, b = 0, c = 2 and d = 1, find the value of ab − bc + cd − da

If a = 3, b = 0, c = 2 and d = 1, find the value of abc − bcd + cda

If a = 3, b = 0, c = 2 and d = 1, find the value of a² + 2b² − 3c²

If a = 3, b = 0, c = 2 and d = 1, find the value of a² + b² − c² + d²

If a = 3, b = 0, c = 2 and d = 1, find the value of 2a² − 3b² + 4c² − 5d²

Find the value of 5x² – 3x + 2, when x = 2.

Find the value of 3x³ – 4x² + 5x – 6, when x = − 1.

Show that the value of x³ – 8x² + 12x – 5 is zero, when x = 1.

State true and false:

The value of x + 5 = 6, when x = 1

State true and false:

The value of 2x – 3 = 1, when x = 0

State true and false:

`(2"x"-4)/("x"+1)` = − 1, when x = 1

If x = 2, y = 5 and z = 4, find the value of the following:

`"x"/(2"x"^2)`

If x = 2, y = 5 and z = 4, find the value of the following:

`"xz"/"yz"`

If x = 2, y = 5 and z = 4, find the value of the following:

z^x

If x = 2, y = 5 and z = 4, find the value of the following:

y^x

If x = 2, y = 5 and z = 4, find the value of the following:

`("x"^2"y"^2"z"^2)/"xz"`

If x = 2, y = 5 and z = 4, find the value of the following:

`(5"x"^4"y"^2"z"^2)/(2"x"^2)`

If x = 2, y = 5 and z = 4, find the value of the following:

xy ÷ y²z

If x = 2, y = 5 and z = 4, find the value of the following:

`("x"^2"y"^"x")/"x"`

If a = 3, find the values of a² and 2^a.

If m = 2, find the difference between the values of 4m³ and 3m⁴.

Evaluate:

(23 – 15) + 4

Evaluate:

5x + (3x + 7x)

Evaluate:

6m – (4m – m)

Evaluate:

(9a – 3a) + 4a

Evaluate:

35b – (16b + 9b)

Evaluate:

(3y + 8y) – 5y

Simplify:

12x − (5x + 2x)

Simplify:

10m + (4n − 3n) − 5n

Simplify:

(15b − 6b) − (8b + 4b)

Simplify:

− (− 4a − 8a)

Simplify:

x − (x − y) − (− x + y)

Simplify:

p + (− q − r − s) − (p − q − r)

Simplify:

(a + b) − (c + d) − (e − f)

Simplify:

3x + (8x − 5x) − (7x − x)

Simplify:

a − (a − b − c)

Simplify:

6a² + (2a² − a²) − (a² − b²)

Simplify:

2m − (3m + 2n − 6n)

Simplify:

− m − n − (− m) − m

Simplify:

x + y − (x + `overline("y"-"x"))`

Simplify:

25y − (5x − 10y + 6x − 3y)

Simplify:

`3"x"+(2"x"-overline("x"+2))`

Simplify:

`"a"-(2"a"-overline(4"a"+3"a"))`

Simplify:

`5"x"^2-(3"x"-overline("x"^2-4))`

Simplify:

− (y − x) − (x + y − `overline(2"x"+"y")`)

Simplify:

x − (y − z) + x + (y − z) + y − (z + x)

Simplify:

x − [y + {x − (y + x)}]

Simplify:

4x + 3 (2x − 5y)

Simplify:

2 (3a − b) − 5 (a − 3b)

Simplify:

p + 2 (q − r − p)

Simplify:

`"a"−[−{−(a−overline("b"-"c"))}]`

Simplify:

3x − [5y − {6y + 2 (10y − x)}]

Simplify:

`5{"a"^2-"a"("a"-overline("a"-2))}`

Fill in the blank:

2a + b − c = 2a + (.............)

Fill in the blank:

3x − z + y = 3x − (..............)

Fill in the blank:

6p − 5x + q = 6p − (...........)

Fill in the blank:

a + b − c + d = a + (...............)

Fill in the blank:

5a + 4b + 4x − 2c = 4x − (...........)

Fill in the blank:

7x + 2z + 4y − 3 = − 3 + 4y + (.............)

Fill in the blank:

3m − 2n + 6 = 6 − (............)

Fill in the blank:

2t + r − p − q + s = 2t + r − (..................)

Insert the bracket as indicated:

x − 2y = − (...................)

Insert the bracket as indicated:

m + n − p = − (.............)

Insert the bracket as indicated:

a + 4b − 4c = a + (...............)

Insert the bracket as indicated:

a − 3b + 5c = a − (..............)

Insert the bracket as indicated:

x² − y² + z² = x² − (..................)

Insert the bracket as indicated:

m² + x² − p² = − (...................)

Insert the bracket as indicated:

2x − y + 2z = 2z − (....................)

Insert the bracket as indicated:

ab + 2bc − 3ac = 2bc − (...............)

Find the value of 3ab + 10bc – 2abc when a = 2, b = 5 and c = 8.

If x = 2, y = 3 and z = 4, find the value of 3x² – 4y² + 2z².

If x = 3, y = 2 and z = 1; find the value of x^y

If x = 3, y = 2 and z = 1; find the value of y^x

If x = 3, y = 2 and z = 1; find the value of 3x² − 5y²

If x = 3, y = 2 and z = 1; find the value of 2x – 3y + 4z + 5

If x = 3, y = 2 and z = 1; find the value of y² – x² + 6z²

If x = 3, y = 2 and z = 1; find the value of xy + y²z – 4zx

If P = − 12x² – 10xy + 5y², Q = 7x² + 6xy + 2y², and R = 5x² + 2xy + 4y² ; find P – Q

If P = − 12x² – 10xy + 5y², Q = 7x² + 6xy + 2y², and R = 5x² + 2xy + 4y² ; find Q + P

If P = − 12x² – 10xy + 5y², Q = 7x² + 6xy + 2y², and R = 5x² + 2xy + 4y² ; find P – Q + R

If P = − 12x² – 10xy + 5y², Q = 7x² + 6xy + 2y², and R = 5x² + 2xy + 4y² ; find P + Q + R

If x = a² – bc, y = b² – ca, and z = c² – ab; find the value of ax + by + cz

If x = a² – bc, y = b² – ca, and z = c² – ab; find the value of ay – bx + cz

Multiply and then evaluate:

(4x + y) and (x – 2y); when x = 2 and y = 1.

Multiply and then evaluate:

(x² – y) and (xy – y²); when x = 1 and y = 2.

Multiply and then evaluate:

(x – 2y + z) and (x – 3z); when x = − 2, y = − 1 and z = 1.

Simplify:

5 (x + 3y) – 2 (3x – 4y)

Simplify:

3x – 8 (5x – 10)

Simplify:

6 {3x – 8 (5x – 10)}

Simplify:

3x – 6 {3x – 8 (5x – 10)}

Simplify:

2 (3x² – 4x – 8) – (3 – 5x – 2x²)

Simplify:

`8"x"−(3"x"−overline(2"x"-3))`

Simplify:

`12"x"^2-(7"x"-overline(3"x"^2+15))`

If x = − 3, find the value of 2x³ + 8x² – 15.