Question

Using an identity, find the square of 101.

• A. $10201$
• B. $10201$
• C. $10204$
• D. $10401$

Answer 1

The correct option is A $10201$

$\text{To find:}(101{)}^2$

$\left(101{)}^2\text{can be written as}\right(100+1{)}^2.$

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

we get,
$(100+1{)}^2={100}^2+2\times 100\times 1+1^2$
$=10000+200+1$
$=10201$