Question

The value of (99)${}^2$ is_____

• A. 9901
• B. 9801
• C. 9981
• D. 9991

Answer 1

The correct option is B 9801

(99)${}^2$ = (100 - 1)${}^2$.

Using the identity:

(a-b)${}^2$ = (a)${}^2$-2ab+(b)${}^2$,

(100 - 1)${}^2$ = (100)${}^2$-2(1)(100)+(1)${}^2$
= 9801.