7. \(\frac{x}{8}+\frac{1}{5}=4\)

Вычтем \(\frac{1}{5}\): \(\frac{x}{8}=4-\frac{1}{5}=\frac{19}{5}\).

Умножим на 8: \(x=\frac{152}{5}=30\frac{2}{5}\).

Ответ: \(x=\frac{152}{5}\).