Question 92 (i)
Factorise the following using the identity a2−b2=(a+b)(a−b).
x2−9
We have, x2−9=x2−32=(x−3)(x+3) [∵a2−b2=(a−b)(a+b)]
Question 92 (vi)
9x2−1
Question 92 (xi)
y3−y9
Question 92 (xiii)
x28−y218
Question 92 (xxviii)
x4−y4+x2−y2
Question 92 (xxvi)
(a−b)2−(b−c)2