Сравните значения выражений:
а) $56 \cdot \frac{2}{7}$ и $56 : \frac{7}{2}$
$56 \cdot \frac{2}{7} = \frac{56 \cdot 2}{7} = \frac{8 \cdot 2}{1} = 16$
$56 : \frac{7}{2} = 56 \cdot \frac{2}{7} = \frac{56 \cdot 2}{7} = \frac{8 \cdot 2}{1} = 16$
16 = 16

б) 9 : 0,36 и 0,9
25 > 0,9

в) $\frac{3}{5} - \frac{5}{4}$ и $\frac{3}{8} \cdot (-\frac{5}{4})$
$\frac{3}{5} - \frac{5}{4} = \frac{12}{20} - \frac{25}{20} = -\frac{13}{20}$
$\frac{3}{8} \cdot (-\frac{5}{4}) = -(\frac{3}{8} \cdot \frac{5}{4}) = -\frac{15}{32}$
$-\frac{13}{20}$ и $-\frac{15}{32}$
$-\frac{104}{160}$ < $-\frac{75}{160}$

г) $\frac{1}{8} - \frac{1}{9}$ и $\frac{1}{9} - \frac{1}{10}$
$\frac{1}{8} - \frac{1}{9} = \frac{9}{72} - \frac{8}{72} = \frac{1}{72}$
$\frac{1}{9} - \frac{1}{10} = \frac{10}{90} - \frac{9}{90} = \frac{1}{90}$
$\frac{1}{72}$ > $\frac{1}{90}$.