Question 85 (xi)
Expand the following, using suitable identities.
(2a3+b3)(2a3−b3)
We have, (2a3+b3)(2a3−b3)=(2a3)2−(b3)2 [using the identity, (a+b)(a−b)=a2−b2] =49a2−19b2
Question 85 (ix)
(2x3−23)(2x3+2a3)
Question 85 (iv)
(23x−32y)2
Question 85 (vi)
(x+3)(x+7)