5.501 Вычислите: а) (\frac{2}{5})^{2}; 6) (\frac{3}{4}-\frac{2}{3})^{2}; B) (\frac{1}{2})^{3}-(\frac{1}{4})^{2}.

a)

\[(\frac{2}{5})^2 = \frac{2^2}{5^2} = \frac{4}{25}\]

Ответ: \(\frac{4}{25}\)

б)

\[(\frac{3}{4} - \frac{2}{3})^2 = (\frac{9}{12} - \frac{8}{12})^2 = (\frac{1}{12})^2 = \frac{1}{144}\]

Ответ: \(\frac{1}{144}\)

в)

\[(\frac{1}{2})^3 - (\frac{1}{4})^2 = \frac{1}{8} - \frac{1}{16} = \frac{2}{16} - \frac{1}{16} = \frac{1}{16}\]

Ответ: \(\frac{1}{16}\)