Question

Simplify the following:
(a+b)³-a³-b³=? ​

Answer 1

(a + b)³ - a³ - b³

Therefore, the formula used in this question is- (a+b)³=a³ + 3a²b + 3ab² + b³,

= (a³ + 3a²b + 3ab² + b³) -a³ - b³

= a³ + 3a²b + 3ab² + b³ - a³ -b³

= (a³ - a³) + (b³ - b³) + 3a²b + 3ab²

= 3a²b + 3ab²

= 3ab (a + b) Answer.

Answer 2

Answer:

(a + b)³ - a³ - b³

Therefore, the formula used in this question is- (a+b)³=a³ + 3a²b + 3ab² + b³,

= (a³ + 3a²b + 3ab² + b³) -a³ - b³

= a³ + 3a²b + 3ab² + b³ - a³ -b³

= (a³ - a³) + (b³ - b³) + 3a²b + 3ab²

= 3a²b + 3ab²

= 3ab (a + b) Answer.