Question

Th square of 98 is equal to

• A. 9624
• B. 9604
• C. 9616
• D. 9684

Answer 1

The correct option is B

9604

$(98{)}^2$ can be written as

$(100-2{)}^2$

$={100}^2+2^2-2\times 100\times 2\left[\right(x-y{)}^2=x^2+y^2-2xy]$

$=10000+4-400$

$=9604$