Question

Using the formula (a-b)^2=(a^2-2ab+b^2),evaluate :
(i)(196)^2 (ii)(689)^2

Answer 1

1. (196)^2=(200-4)^2
=(200)^2-2×200×4+(4)^2
=40000-1600+16
=38416 2. (689)^2 =(700-11)^2 =(700)^2-2×700×11+(11)^2 =490000-15400+121 =474721