3) 5 8/11 - 10/11 =

3) $$\begin{aligned}5\frac{8}{11} - \frac{10}{11} &= 4 + \frac{11}{11} + \frac{8}{11} - \frac{10}{11} = 4 + \frac{19}{11} - \frac{10}{11} = 4\frac{9}{11}\\\\&=\frac{4 \cdot 11 + 9}{11} = \frac{44+9}{11} = \frac{53}{11} = 4\frac{9}{11}\end{aligned}$$

Ответ: 4 9/11