Question

a plus b whole cube minus a minus b whole cube minus 2b(b square plus 3a square)​

Answer 1

Answer:

(a+b)³=a³+3a²b+3ab²+b³

(a-b)³=a³-3a²b+3ab²-b³

(a+b)³ - (a-b)³ - 2b

= 6a²b+6ab²+2b³-2b

= b(6a²+6ab+2b²-2)

= b(6a(a+b) +2(b²-1))