$$a+5-b = 9\frac{4}{5} + 5 - 4\frac{3}{5} = 9\frac{4}{5} - 4\frac{3}{5} + 5 = 5\frac{1}{5} + 5 = 10\frac{1}{5}$$
Ответ: $$10\frac{1}{5}$$