log (13) x^7 √y/z^4

It depends on where your brackets were meant to be :/

$$\\\frac{log (13) x^7 \sqrt{y}}{z^4}\\\\ OR\\\\ =log (13) x^7 \sqrt{\frac{y}{z^4}}\\\\ =log (13) x^7 \frac{\sqrt{y}}{z^2}\\\\ =\frac{x^7\sqrt{y\;}\;log (13)}{z^2}$$