Question

помогите пожалуйста ​

Answer 1

Ответ:

$1.x + \frac{4}{21} = \frac{2}{3} + \frac{2}{7}$

$x + \frac{4}{21} = \frac{20}{21}$

$x = \frac{ 20}{21} - \frac{4}{21}$

$x = \frac{16}{21}$

$3.( \frac{4}{5} - x) + \frac{13}{20} = \frac{7}{10}$

$\frac{4}{5}- x +\frac{13}{20} = \frac{7}{10}$

$\frac{29}{20} - x = \frac{7}{10}$

$- x = \frac{7}{10} - \frac{29}{20}$

$- x = - \frac{3}{4}$

$x = \frac{3}{4}$

$2.y + \frac{1}{4} = \frac{4}{5} - \frac{3}{10}$

$y + \frac{1}{4} = \frac{1}{2}$

$y = \frac{1}{2} - \frac{1}{4}$

$y = \frac{1}{4}$

$4. \frac{2}{3} - ( \frac{2}{9} + x) = \frac{1}{3}$

$\frac{2}{3} - \frac{2}{9} - x = \frac{1}{3}$

$\frac{4}{9} - x = \frac{1}{3}$

$- x = \frac{1}{3} - \frac{4}{9}$

$- x = - \frac{1}{9}$

$x = \frac{1}{9}$