Question

Вычислите 7,5х(5 2/3 - 4,2)

Answer 1

Ответ:

$\displaystyle 7,5*(5\frac{2}{3}-4,2)=11$

Пошаговое объяснение:

$\displaystyle 7,5*(5\frac{2}{3}-4,2)$

$\displaystyle 1)\ 5\frac{2}{3}-4,2=1\frac{2}{3}-0,2=1\frac{2}{3}-\frac{2}{10}=1\frac{2}{3}-\frac{1}{5}=1\frac{2*5}{3*5}-\frac{1*3}{5*3}=\\\\=1\frac{10}{15}-\frac{3}{15}=1\frac{10-3}{15}=1\frac{7}{15}=\frac{22}{15}$

$\displaystyle 2)\ 7,5*\frac{22}{15}=7\frac{5}{10}*\frac{22}{15}=7\frac{1}{2}*\frac{22}{15}=\frac{15}{2}*\frac{22}{15}=\frac{15*2*11}{2*15}=11$