Applicare la formula: $x,\:a$$=eval\left(x,a\right)$, dove $a=x=-2$, $x=\frac{4}{5}x^2$ e $x;a=\frac{4}{5}x^2,\:x=-2$

Applicare la formula: $a^b$$=a^b$, dove $a=-2$, $b=2$ e $a^b={\left(-2\right)}^2$

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=4$, $b=5$, $c=4$, $a/b=\frac{4}{5}$ e $ca/b=4\left(\frac{4}{5}\right)$

Applicare la formula: $ab$$=ab$, dove $ab=4\cdot 4$, $a=4$ e $b=4$