Question

Evaluate the following using suitable identity,
$213\times 187$

Answer 1

$213\times 187$

$\Rightarrow (200+13)(200-13)$

$\Rightarrow (200{)}^2-(13{)}^2$ $\left[\right(a+b\left)\right(a-b)=a^2-b^2]$

$\Rightarrow$ 40000 - 169

$\Rightarrow$ 39831