Решите 2 1/7 : 4 1/6 * 2 1/3; (7 1/3 + 2 1/4) : 1/4 - 30 5/6

Решите задачу:

$2 \frac{1}{7} :4 \frac{1}{6} *2 \frac{1}{3} = \frac{15}{7} : \frac{25}{6} * \frac{7}{3} = \frac{15*6*7}{7*25*3}= \frac{6}{5}=1 \frac{1}{5}$
$(7 \frac{1}{3} +2 \frac{1}{4} ): \frac{1}{4} -30 \frac{5}{6} =( \frac{22}{3} + \frac{9}{4}): \frac{1}{4} - \frac{185}{6} =( \frac{22*4+9*3}{12}): \frac{1}{4}- \frac{185}{6} = \\ =\frac{115*4}{12*1} - \frac{185}{6}= \frac{115}{3} - \frac{185}{6} = \frac{115*2-185}{6} = \frac{45}{6}= \frac{15}{2} =7 \frac{1}{2}$