Помогите пожалуйста решить

1) $\frac{1}{x}+ \frac{1}{1 \frac{2}{7}*x }= \frac{4}{9}$
$\frac{1}{x}+ \frac{1}{ \frac{9}{7}x } = \frac{4}{9}$
$\frac{1}{x}+ \frac{1}{ \frac{9x}{7} } = \frac{4}{9}$
$\frac{1}{x} + \frac{7}{9x} = \frac{4}{9}$
$\frac{16}{9x}= \frac{4}{9}$
144=36x
36x=144
x=4, x≠0

2) $\frac{2}{ \frac{8}{5}x} - \frac{1}{x} = \frac{1}{12}$
   $\frac{5}{4x} - \frac{1}{x} = \frac{1}{12}$
   $\frac{1}{4x} = \frac{1}{12}$
4x=12
x=3, x≠0

3) $\frac{2}{ \frac{4x}{3} } - \frac{1}{x}= \frac{1}{4}$
$\frac{3}{2x}- \frac{1}{x} = \frac{1}{4}$
$\frac{1}{2x} = \frac{1}{4}$
2x=4
x=2, x≠0