Question

solve 8×(a + b )³- ( a - b)³​

Answer 1

Answer:

8(a+b)³ - (a-b)³

= (2)³ × (a+b)³ - (a-b)³

= (2a+2b)³ - (a-b)³

since, a³-b³ = (a-b)(a²+ab+b²)

= {(2a+2b)-(a-b)}(4a²+8ab+4b²+2a²-2ab+2ab-2b²+a²-2ab+b²)

= (a+3b)(7a²+6ab+3b²)