Question

I dont know how to answer this

Answer 1

$\bold {We \: know \: that,}$

$\bold{ {9}^{2} = 81}$

$= \sqrt{(9 {}^{2} }) {}^{ - 2}$

$= \sqrt{(9) {}^{ - 2 \times 2} }$

$= \sqrt{(9) {}^{ - 4} }$

$= (9) {}^{ - 4 \times \frac{1}{2} }$

$= (9) {}^{ - 2}$

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

$\boxed{ = \frac{1}{81}}$