Factorise (a) 16a2+88a+121
(b) 144-24x+x2
(a) It can be factorised using this identity, a2+b2+2ab = (a+b)2
16a2 can be written as (4a)2 and 121 as (11)2
(4a)2 + (11)2 + 2*4a*11 = (4a+11)2
Thus, 16a2+88a+121 = (4a+11)2
(b) It can be factorised using this identity, a2+b2-2ab = (a-b)2
144 can be written as (12)2.
(12)2 + (x)2 - 2*12*x = (12-x)2
Thus, 144-24x+x2 = (12-x)2