Решение:

a) $$2 \frac{2}{15} - 1 \frac{1}{16} = 2 \frac{32}{240} - 1 \frac{15}{240} = 1 \frac{17}{240}$$

б) $$\frac{-1,9+7,3}{2,4} = \frac{5,4}{2,4} = \frac{54}{24} = \frac{9}{4} = 2 \frac{1}{4} = 2,25$$

Ответ: a) $$1 \frac{17}{240}$$, б) $$2,25$$