Question

factorise using a³-b³ formula
(a+2b)³-(a-2b)³​

Answer 1

Answer:

STEP 1 :

1.1 Evaluate : (a+2b)3 = a3+6a2b+12ab2+8b3

1.2 Evaluate : (a-2b)3 = a3-6a2b+12ab2-8b3

STEP 2 :

Pulling out like terms

2.1 Pull out like factors :

12a2b + 16b3 = 4b • (3a2 + 4b2)

Final result :

4b • (3a2 + 4b2)