2. \(\frac{x}{3}-\frac{2}{5}=4\)

Прибавим \(\frac{2}{5}\): \(\frac{x}{3}=4+\frac{2}{5}=\frac{22}{5}\).

Умножим на 3: \(x=\frac{66}{5}=13\frac{1}{5}\).

Ответ: \(x=\frac{66}{5}\).