Factorise the following:
(i) 4(i) 4x 2 + 20x + 25 = (2x) 2 + 2 × 2x × 5 + 5 2= (2x + 5)2 [∵
(i) 4x 2 + 20x + 25 = (2x) 2 + 2 × 2x × 5 + 5 2
= (2x + 5)2 [∵