3)(5целых6/7+3целых5/21)×2целых1/10=;4)(7целых5/12-3целых1/6)×2целых2/17 поиогите...

$( 5\frac{6}{7} + 3\frac{5}{21} )* 2\frac{1}{10} =( \frac{41}{7} + \frac{68}{21} )* \frac{21}{10}= ( \frac{123}{21} + \frac{68}{21} )* \frac{21}{10}= \frac{191}{21} * \frac{21}{10}= \frac{191}{10}=19\frac{1}{10}$ =19,1
$(7\frac{5}{12}-3 \frac{1}{6} )*$ $2\frac{2}{17} =( \frac{89}{12} - \frac{19}{6} )* \frac{36}{17}= ( \frac{89}{12} - \frac{38}{6} )* \frac{36}{17}=\frac{51}{12} * \frac{36}{17}= \frac{153}{17}=9$