The value of $\frac{7.83\times 7.83-1.17\times 1.17}{6.66}$ is :

The correct option is A $9$
Given, $\frac{7.83\times 7.83-1.17\times 1.17}{6.66}$.

We know, $a^2-b^2=(a+b)(a-b)$.

Then,

$\frac{7.83\times 7.83-1.17\times 1.17}{6.66}$

$=\frac{(7.83{)}^2-(1.17{)}^2}{6.66}$

$=\frac{(7.83+1.17)(7.83-1.17)}{6.66}$

$=\frac{9\times 6.66}{6.66}=9$.

Therefore, option $A$ is correct.