Решите уравнение (1 - 7/10) х = 2 1/4 (1/4 + 1/5) х = 1 4/5 (3 1/8 + 1 3/4) х = 2 1/6 (2...

1) $1) (1- \frac{7}{10} )x=2 \frac{1}{4}$
$1- \frac{7}{10} = \frac{3}{10}$
$\frac{3}{10} x= \frac{9}{4}$
$x= \frac{9}{4} : \frac{3}{10} = \frac{9}{4} * \frac{10}{3} = \frac{15}{2}$
x=7.5
2) $(\frac{1}{4} + \frac{1}{5} )x=1 \frac{4}{5}$
$\frac{1}{4} + \frac{1}{5} = \frac{1*5}{4*5} + \frac{1*4}{5*4} = \frac{5}{20} + \frac{4}{20} = \frac{9}{20}$
$\frac{9}{20} x=1 \frac{4}{5}$
$x= \frac{9}{5} : \frac{9}{20} = \frac{9}{5}* \frac{20}{9} =4$
x=4