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

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=3$, $b=5$, $c=10$, $a/b=\frac{3}{5}$ e $ca/b=10\cdot \left(\frac{3}{5}\right)$

Applicare la formula: $ab$$=ab$, dove $ab=10\cdot 3$, $a=10$ e $b=3$

Applicare la formula: $\frac{a}{b}$$=\frac{a}{b}$, dove $a=30$, $b=5$ e $a/b=\frac{30}{5}$