Question

$\frac{(383.08{)}^2-({303.08}^2)}{686.16}$ =.

• A. 8
• B. 383.08
• C. 80

Answer 1

The correct option is C 80

Using the identity
$a^2$ - $b^2$ = $(a+b)(a-b)$,

${383.08}^2$ - ${303.08}^2$
= (383.08 + 303.08)(383.08 - 303.08)
= 686.16 $\times$ 80

Therefore, $\frac{\left({383.08}^2\right)-\left({303.08}^2\right)}{686.16}$ = $\frac{686.16\times 80}{686.16}$

= 80