$$\left. \begin{array} { l } { x = 4 , y = 2 , m = 17 \frac { x ^ { m + n } - n } { x ^ { m } - n } } \\ { x = 4 , y = 2 , m = 1 n = 2 , } \right.$$
$x=4$
$y=2$
$m=n\text{ and }-n^{2}+n\times 4^{n}-17\times 16^{n}=-17n\text{ and }n\neq 4^{n}\text{ and }\left(n\neq \frac{\log_{2}\left(n\right)}{2}\text{ or }n\leq 0\right)$
