Математика 5 класс 693 плиз

$\frac{\frac{2}{3} }{ \frac{4x}{9} - \frac{4}{9} } + \frac{1}{20} = \frac{4}{5} \\ \frac{\frac{2}{3} }{ \frac{4x}{9} - \frac{4}{9} } = \frac{4}{5} - \frac{1}{20} \\ \frac{\frac{2}{3} }{ \frac{4x}{9} - \frac{4}{9} } = \frac{3}{4} \\ \frac{4x}{9} - \frac{4}{9} = \frac{2 \times 4}{3 \times 3} \\ \frac{4x}{9} - \frac{4}{9} = \frac{8}{9} \\ \frac{4x}{9} = \frac{8}{9} - \frac{4}{9} \\ \frac{4x}{9} = \frac{4}{9} \\ 4x \times 9 = 9 \times 4 \\ 36x = 36 \\ x = 1$
Ответ: 1