Advertisements
Advertisements
Question
Simplify (2x – 5y)3 – (2x + 5y)3.
Advertisements
Solution
(2x – 5y)3 – (2x + 5y)3 = [(2x)3 – (5y)3 – 3(2x)(5y)(2x – 5y)] – [(2x)3 + (5y)3 + 3(2x)(5y)(2x + 5y)] ...[Using identity, (a – b)3 = a3 – b3 – 3ab and (a + b)3 = a3 + b3 + 3ab]
= (2x)3 – (5y)3 – 30xy(2x – 5y) – (2x)3 – (5y)3 – 30xy(2x + 5y)
= –2(5y)3 – 30xy(2x – 5y + 2x + 5y)
= –2 × 125y3 – 30xy(4x)
= –250y3 – 120x2y
APPEARS IN
RELATED QUESTIONS
Write the following cube in expanded form:
(2x + 1)3
Write the following cube in expanded form:
`[3/2x+1]^3`
Factorise the following:
27y3 + 125z3
Give possible expression for the length and breadth of the following rectangle, in which their area are given:
| Area : 25a2 – 35a + 12 |
Simplify the following products:
`(1/2a - 3b)(1/2a + 3b)(1/4a^2 + 9b^2)`
Simplify the following products:
`(x^3 - 3x^2 - x)(x^2 - 3x + 1)`
Simplify: `(a + b + c)^2 - (a - b + c)^2`
Simplify (a + b + c)2 + (a - b + c)2 + (a + b - c)2
If a2 + b2 + c2 = 16 and ab + bc + ca = 10, find the value of a + b + c.
If \[x - \frac{1}{x} = - 1\] find the value of \[x^2 + \frac{1}{x^2}\]
If x + y + z = 8 and xy +yz +zx = 20, find the value of x3 + y3 + z3 −3xyz
If a + b + c = 0, then write the value of \[\frac{a^2}{bc} + \frac{b^2}{ca} + \frac{c^2}{ab}\]
If \[x + \frac{1}{x}\] 4, then \[x^4 + \frac{1}{x^4} =\]
If \[3x + \frac{2}{x} = 7\] , then \[\left( 9 x^2 - \frac{4}{x^2} \right) =\]
If a2 - 5a - 1 = 0 and a ≠ 0 ; find:
- `a - 1/a`
- `a + 1/a`
- `a^2 - 1/a^2`
If m - n = 0.9 and mn = 0.36, find:
m2 - n2.
If `x + (1)/x = "p", x - (1)/x = "q"`; find the relation between p and q.
Simplify:
(4x + 5y)2 + (4x - 5y)2
Factorise the following:
9y2 – 66yz + 121z2
Expand the following:
`(1/x + y/3)^3`
