Question

Solve
$\left(\frac{3^{-7}}{3^{-10}}\right)\times 3^{-5}$

Answer 1

Let $a=\left(\frac{3^{-7}}{3^{-10}}\right)\times 3^{-5}$.

$=3^{(-7-(-10\left)\right)}\times 3^{-5}$

$=3^3\times 3^{-5}$

$=3^{(3-5)}=3^{-2}$

$a=\frac{1}{3^2}=\frac{1}{9}$

$\therefore \left(\frac{3^{-7}}{3^{-10}}\right)\times 3^{-5}=\frac{1}{9}$