Tìm giá trị của \(x,\) biết: \(x + \frac{3}{{10}} = \frac{{ - 7}}{{25}}:\frac{2}{5}\).

Đáp án: \( - 1\)

Ta có: \(x + \frac{3}{{10}} = \frac{{ - 7}}{{25}}:\frac{2}{5}\)

\(x + \frac{3}{{10}} = \frac{{ - 7}}{{25}}.\frac{5}{2}\)

\(x + \frac{3}{{10}} = \frac{{ - 7}}{{10}}\)

\(x = \frac{{ - 7}}{{10}} - \frac{3}{{10}}\)

\(x = \frac{{ - 10}}{{10}}\) hay \(x = - 1\).

Vậy \(x = - 1\).