20) \(-2\frac{2}{5}\) + 3\(\frac{2}{5}\)

Решение:

\(-2\frac{2}{5}\) + \(3\frac{2}{5}\) = \(-\frac{12}{5}\) + \(\frac{17}{5}\) = \(\frac{5}{5}\) = 1

Ответ: 1