Question

expand (7x - 9y) ^3 = ______​

Answer 1

Answer:

Please mark my answer as the brainliest answer.

Hope it helps you!!!

Answer 2

Answer:

Let us simplify the expression, we get

(7x – 9y)3 = (7x)3 – [ 3 × (7x)2 × 9y ] + [3 × (7x) × (9y)2 ] – (9y)3

By using the formula,

(a – b)3 = a3 – 3a2b + 3ab2 – b3

Here, a = 7x, b = -9y

Now, substitute the value we get

= 343x3 – [3 × 49x2 × 9y] + [3 × 7x × 81y2] – 729y3

= 343x3 – 1323x2y + 1701xy2 – 729y3

∴ (7x – 9y)3 = 343x3 – 1323x2y + 1701xy2 – 729y3