Question 92 (v)
Factorise the following using the identity a2−b2=(a+b)(a−b).
28ay2−175ax2
We have, 28ay2−175ax2=7a(4y2−25x2)=7a[(2y)2−(5x)2]=7a(2y−5x)(2y+5x)
Question 92 (vii)
25ax2−25a
Question 92 (xxv)
16x4−625y4