Question

Use the identity $(a+b)(a-b)=a^2-b^2$ to evaluate:
$33\times 27$.

• A. $891$
• B. $881$
• C. $981$
• D. $841$

Answer 1

The correct option is A $891$

We know, $33\times 27=(30+3)\times (30-3)$ .
Applying the formula $(a+b)(a-b)=a^2-b^2$, where $a=30,b=3$,

we get,
$33\times 27=(30+3)\times (30-3)={30}^2-3^2=900-9=891$ .

Therefore, option $A$ is correct.