$$\frac{4}{5} = \frac{4 \cdot 6}{5 \cdot 6} = \frac{24}{30}$$
$$\frac{7}{8} = \frac{7 \cdot 6}{8 \cdot 6} = \frac{42}{48}$$
$$\frac{13}{15} = \frac{13 \cdot 6}{15 \cdot 6} = \frac{78}{90}$$
$$\frac{37}{40} = \frac{37 \cdot 6}{40 \cdot 6} = \frac{222}{240}$$
Ответ: $$\frac{4}{5} = \frac{24}{30}$$, $$\frac{7}{8} = \frac{42}{48}$$, $$\frac{13}{15} = \frac{78}{90}$$, $$\frac{37}{40} = \frac{222}{240}$$