Find the Cube Of: 2a - 5b - Mathematics

Find the cube of: 2a - 5b

Sum

Using (a - b)³
= a³ - b³ - 3ab (a - b)
(2a - 5b)
= (2a)³- (5b)³ - 3(2a) (5b) (2a - 5b)
= 8a³ - 125b³ - 30ab (2a - 5b)
= 8a³- 125b³ - 60a²b + 150ab².

shaalaa.com

Is there an error in this question or solution?

Chapter 4: Expansions - Exercise 4.2

Chapter 4 Expansions
Exercise 4.2 | Q 1.1

Find the cube of : 5a + 3b

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

Expand : (3x + 5y + 2z) (3x - 5y + 2z)

If a ≠ 0 and `a - 1/a` = 4; find: `(a^2 + 1/a^2)`

If `"a" - (1)/"a" = 7`, find `"a"^2 + (1)/"a"^2 , "a"^2 - (1)/"a"^2` and `"a"^3 - (1)/"a"^3`

If p - q = -1 and pq = -12, find p³ - q³

If m - n = -2 and m³ - n³ = -26, find mn.

Simplify:

`("a" + 1/"a")^3 - ("a" - 1/"a")^3`

If `x^2 + 1/x^2` = 23, then find the value of `x + 1/x` and `x^3 + 1/x^3`

(p + q)(p² – pq + q²) is equal to _____________