Question

I don't understand exponents

Answer 1

You must apply the law of exponets.

You must apply only at the same letter. X or Y

$\frac{x^{m}}{x^{n}} = x^{m-n}$

$\frac{x^{3}}{x^{6}} = x^{3-6} =x^{-3}$

$\frac{y^{3}}{y^{-6}} = y^{(3-(-6))} =y^{3+6}=y^{9}$

$\frac{20x^{3}y^{3}}{32x^{6}y^{-6}} = \frac{20x^{(3-6)}y^{(3-(-6))}}{32}=\frac{20x^{(-3)}y^{(3+6)}}{32}=\frac{20x^{(-3)}y^{(9)}}{32}$

But 
$x^{-n} = \frac{1}{x^{n}}$
Then

$\frac{20x^{3}y^{3}}{32x^{6}y^{-6}} = \frac{20x^{(-3)}y^{(9)}}{32}=\frac{20y^{9}}{32x^{3}}=\frac{10y^{9}}{16x^{3}}=\frac{5y^{9}}{8x^{3}}$