# How do you simplify x^7/x^15 and write it using only positive exponents?

Using the rule for exponents: ${z}^{\textcolor{red}{a}} / {z}^{\textcolor{b l u e}{b}} = \frac{1}{z} ^ \left(\textcolor{b l u e}{b} - \textcolor{red}{a}\right)$ gives:
$\frac{1}{x} ^ \left(\textcolor{b l u e}{15} - \textcolor{red}{7}\right) = \frac{1}{x} ^ 8$