Answer:
139/4
Explanation:
and find that\[
\frac{4}{7}\cdot \frac{13}{13} = \frac{4\cdot 13}{91}=\frac{52}{91}, \text{and}
\]\[
\frac{8}{13}\cdot \frac{7}{7} = \frac{8\cdot 7}{91} = \frac{56}{91}.
\]Thus $\frac{8}{13}$ is larger than $\frac{4}{7}$, which tells us that $-\frac{8}{13}$ is smaller than $-\frac{4}{7}$. Thus, $x=-22$, $y=-\frac{8}{13}$, and\begin{align*}
\frac{x-y}{y}&=\frac{-22-\left(-\frac{8}{13}\right)}{-\frac{8}{13}}\\
&=\left(-22\cdot \frac{13}{13}+\left(\frac{8}{13}\right)\right)\cdot \left(-\frac{13}{8}\right)\\
&=\left(\frac{-286+8}{13}\right)\cdot \left(-\frac{13}{8}\right)\\
&=\left(-\frac{278}{13}\right)\cdot \left(-\frac{13}{8}\right)\\
&=\boxed{\frac{139}{4}}.
\end{align*}