Applicare la formula: $ab$$=ab$, dove $ab=9\cdot 5\cdot \left(\frac{2}{3}\right)$, $a=9$ e $b=5$

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=2$, $b=3$, $c=45$, $a/b=\frac{2}{3}$ e $ca/b=45\cdot \left(\frac{2}{3}\right)$

Applicare la formula: $ab$$=ab$, dove $ab=45\cdot 2$, $a=45$ e $b=2$

Applicare la formula: $\frac{a}{b}$$=\frac{a}{b}$, dove $a=90$, $b=3$ e $a/b=\frac{90}{3}$