Giải bài 5 trang 25 toán 7 tập 1 chân trời sáng tạo.
a) $\frac{2}{9}:x+\frac{5}{6}=0,5$
$\frac{2}{9}:x = 0,5 - \frac{5}{6}$
$\frac{2}{9}:x = 0,5 - \frac{5}{6}$
$\frac{2}{9}:x = - \frac{1}{3}$
$x = \frac{3}{2}$
b) $\frac{3}{4}-\left ( x-\frac{2}{3} \right ) = 1\frac{1}{3}$
$\left ( x-\frac{2}{3} \right ) = \frac{3}{4}-\frac{4}{3}$
$\left ( x-\frac{2}{3} \right ) = -\frac{7}{12}$
$x = -\frac{7}{12} + \frac{2}{3}$
$x = \frac{1}{12}$
c) $1\frac{1}{4}:\left ( x-\frac{2}{3} \right ) = 0,75$
$\left ( x-\frac{2}{3} \right ) = 1\frac{1}{4} : 0,75$
$\left ( x-\frac{2}{3} \right ) = \frac{5}{4} : \frac{3}{4}$
$\left ( x-\frac{2}{3} \right ) = \frac{5}{3}$
$x = \frac{5}{3} + \frac{2}{3}$
$x = \frac{7}{3}$
d) $ \left (-\frac{5}{6}x+ \frac{5}{4}\right ):\frac{3}{2} = \frac{4}{3}$
$ -\frac{5}{6}x+ \frac{5}{4} = \frac{4}{3} .\frac{3}{2}$
$ -\frac{5}{6}x+ \frac{5}{4} = 2$
$ -\frac{5}{6}x = 2 - \frac{5}{4}$
$ -\frac{5}{6}x = \frac{3}{4}$
$x = \frac{3}{4} : (-\frac{5}{6})$
$x = \frac{-9}{10}$