Question

Find the cube of: 4x + 7y

Answer 1

Using (a + b)³
= a³ + b³ + 3ab + (a + b)
(4x + 7y)³
= (4x)³ + (7y)³ + 3(4x) (7y) (4x + 7y)
= 64x³ + 343y³ + 84xy (4x + 7y)
= 64x³ + 343y³ + 336x²y + 588xy².