Question 85 (xv)
Expand the following, using suitable identities.
(0.9p−0.5q)2
We have, (0.9p−0.5q)2=(0.9p)2+(0.5q)2−2×0.9p×0.5q [using the identity, (a−b)2=a2+b2−2ab] =0.81p2+0.25q2−0.9pq
Question 85 (vii)
(2x+9)(2x−7)
Question 85 (ii)
(x2y−xy2)2
Question 85 (xiv)
(7x+5)2
Question 85 (vi)
(x+3)(x+7)