$(8\frac{5}{11} + 19\frac{4}{13}) - (9\frac{4}{13} - 1\frac{6}{11})$
= $(\frac{93}{11} + \frac{251}{13}) - (\frac{121}{13} - \frac{17}{11})$
= $\frac{93}{11} + \frac{251}{13} - \frac{121}{13} + \frac{17}{11}$
= $\frac{93}{11} + \frac{251}{13} + \frac{-121}{13} + \frac{17}{11}$
= $(\frac{251}{13} + \frac{-121}{13}) + (\frac{93}{11} + \frac{17}{11})$
= 10 + 10
= 20
Cho mk câu trả lời hay nhất nhé bạn