Question

Задания 2 и 3
Преобразуйте числовые национальные выражения

Answer 1

$2)(\frac{4}{9}-3\frac{1}{15})*9=(\frac{4}{9}-\frac{46}{15})*9=\frac{4}{9}*9-\frac{46}{15}*9=4-\frac{46*3}{5}=4-\frac{138}{5}=4-27,6=-23,6\\\\Otvet:\boxed{-23,6}$

$3)(1\frac{11}{16}-3\frac{7}{8})*4=(\frac{27}{16}-\frac{31}{8})*4=\frac{27}{16}*4-\frac{31}{8}*4= \frac{27}{4}-\frac{31}{2} =6,75-15,5=-8,75\\\\Otvet:\boxed{-8,75}$

Answer 2

$\displaystyle \tt 1). \ \ \bigg(\frac{17}{10}-\frac{1}{20}\bigg)\cdot\frac{2}{15}=\frac{34-1}{20}\cdot\frac{2}{15}=\frac{33}{10\cdot15}=\frac{11}{50}=0,22;\\\\\\2). \ \ \bigg(\frac{4}{9}-3\frac{1}{15}\bigg)\cdot9=\frac{20-138}{45}\cdot9=-\frac{118}{5}=-23,6;\\\\\\3). \ \ \bigg(1\frac{11}{16}-3\frac{7}{8}\bigg)\cdot4=\frac{27-62}{16}\cdot4=-\frac{35}{4}=-8,75;$