Вычислите:
а) $\frac{3}{7} * 2$;
б) $3 * \frac{1}{6}$;
в) $9 * \frac{5}{6}$;
г) $\frac{2}{5} * 15$;
д) $\frac{1}{4} * 4$;
е) $5 * \frac{1}{5}$.
$\frac{3}{7} * 2 = \frac{3}{7} * \frac{2}{1} = \frac{3 * 2}{7 * 1} = \frac{6}{7}$
$3 * \frac{1}{6} = \frac{3}{1} * \frac{1}{6} = \frac{3 * 1}{1 * 6} = \frac{1 * 1}{1 * 2} = \frac{1}{2}$
$9 * \frac{5}{6} = \frac{9}{1} * \frac{5}{6} = \frac{9 * 5}{1 * 6} = \frac{3 * 5}{1 * 2} = \frac{15}{2} = 7\frac{1}{2}$
$\frac{2}{5} * 15 = \frac{2}{5} * \frac{15}{1} = \frac{2 * 15}{5 * 1} = \frac{2 * 3}{1 * 1} = 6$
$\frac{1}{4} * 4 = \frac{1}{4} * \frac{4}{1} = \frac{1 * 4}{4 * 1} = \frac{1 * 1}{1 * 1} = 1$
$5 * \frac{1}{5} = \frac{5}{1} * \frac{1}{5} = \frac{5 * 1}{1 * 5} = \frac{1 * 1}{1 * 1} = 1$