Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=3$, $b=5$, $c=3$, $a/b=\frac{3}{5}$ e $ca/b=3\cdot \left(\frac{3}{5}\right)\cdot \left(\frac{8}{7}\right)ab$

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

Applicare la formula: $\frac{a}{b}\frac{c}{f}$$=\frac{ac}{bf}$, dove $a=9$, $b=5$, $c=8$, $a/b=\frac{9}{5}$, $f=7$, $c/f=\frac{8}{7}$ e $a/bc/f=\frac{9}{5}\cdot \frac{8}{7}ab$

Applicare la formula: $ab$$=ab$, dove $ab=5\cdot 7$, $a=5$ e $b=7$

Applicare la formula: $ab$$=ab$, dove $ab=9\cdot 8$, $a=9$ e $b=8$