1.выполните действие -3/4 : 5/6 -2целых1/2* 2/5 +1 : 1целых 1/9 скажите как...

$-\frac{3}{4}:\frac{5}{6}-2\frac{1}{2}\cdot\frac{2}{5}+1:1\frac{1}{9}=-1$

1) $-\frac{3}{4}:\frac{5}{6}=-\frac{3}{4}\cdot\frac{6}{5}=-\frac{9}{10}$

2) $2\frac{1}{2}\cdot\frac{2}{5}=\frac{5}{2}\cdot\frac{2}{5}=1$

3) $1:1\frac{1}{9}=1:\frac{10}{9}=1\cdot\frac{9}{10}=\frac{9}{10}$

4) $-\frac{9}{10}-1=\frac{-9-10}{10}=-\frac{19}{10}=-1\frac{9}{10}$

5) $-1\frac{9}{10}+\frac{9}{10}=\frac{9}{10}-\frac{19}{10}=\frac{9-19}{10}=\frac{-10}{10}=-1$