Найдите произведение:
а) $\frac{3}{8} * \frac{8}{3}$;
б) $\frac{8}{9} * \frac{9}{10} * \frac{9}{8}$;
в) $2 * 3 * 4 * \frac{1}{2} * \frac{1}{3} * \frac{1}{4}$.
$\frac{3}{8} * \frac{8}{3} = 1$
$\frac{8}{9} * \frac{9}{10} * \frac{9}{8} = (\frac{8}{9} * \frac{9}{8}) * \frac{9}{10} = 1 * \frac{9}{10} = \frac{9}{10}$
$2 * 3 * 4 * \frac{1}{2} * \frac{1}{3} * \frac{1}{4} = (2 * \frac{1}{2}) * (3 * \frac{1}{3}) * (4 * \frac{1}{4}) = 1 * 1 * 1 = 1$