21. Найдите значение выражений: a) $$(2\frac{1}{4})^2 =$$ b) $$(3\frac{2}{3}):(\frac{4}{9})^2 =$$ v) $$\frac{7}{8}:(4\frac{3}{8}) =$$

Решение:

a) $$(2\frac{1}{4})^2 = (\frac{9}{4})^2 = \frac{81}{16} = 5\frac{1}{16}$$

b) $$(3\frac{2}{3}):(\frac{4}{9})^2 = \frac{11}{3} : \frac{16}{81} = \frac{11}{3} \cdot \frac{81}{16} = \frac{11 \cdot 27}{16} = \frac{297}{16} = 18\frac{9}{16}$$

в) $$\frac{7}{8}:(4\frac{3}{8}) = \frac{7}{8} : \frac{35}{8} = \frac{7}{8} \cdot \frac{8}{35} = \frac{7}{35} = \frac{1}{5}$$

Ответы: a) $$5\frac{1}{16}$$, b) $$18\frac{9}{16}$$, в) $$\frac{1}{5}$$