Applicare la formula: $\ln\left(\frac{a}{b}\right)$$=\ln\left(a\right)-\ln\left(b\right)$, dove $a=zy^2$ e $b=\sqrt[3]{x}$

Applicare la formula: $\ln\left(x^a\right)$$=a\ln\left(x\right)$, dove $a=\frac{1}{3}$

Applicare la formula: $\ln\left(ab\right)$$=\ln\left(a\right)+\ln\left(b\right)$, dove $a=z$ e $b=y^2$

Applicare la formula: $\ln\left(x^a\right)$$=a\ln\left(x\right)$, dove $a=2$ e $x=y$

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=1$, $b=3$, $c=-1$, $a/b=\frac{1}{3}$ e $ca/b=- \left(\frac{1}{3}\right)\ln\left(x\right)$