Question

Evaluate (99)2 by using suitable identities.

Answer 1

(99)2=(100−1)2

(100−1)2 is of the form (a−b)2=a2+b2−2ab where a=100,b=1

∴(100−1)2=1002+12−2×100×1

=10000+1−200=10000−199=9801