Question

Use identities to evaluate ${201}^2$

• A. 40401
• B. 40411
• C. 41401
• D. 40141

Answer 1

The correct option is A

40401

Use the identity $(a+b{)}^2$ = $a^2$ + $b^2$ + 2ab

201 = 200 + 1

Substituting 200 and 1 in the places of a and b respectively,

. $(200+1{)}^2$ = ${200}^2$ + $1^2$ + $(2\times 200\times 1$)

= 40000 + 1 + 400

= 40401