Tính A = -5/17 * -9/23 + 9/23 * -22/17 + 11 9/23

* Hướng dẫn giải

$$\begin{gathered} A=\frac{-5}{17}.\frac{-9}{23}+\frac{9}{23}.\frac{-22}{17}+11\frac{9}{23} \\ =\frac{5}{17}.\frac{9}{23}+\frac{9}{23}.\frac{-22}{17}+11+\frac{9}{23} \\ =\frac{9}{23}\left(\frac{5}{17}+\frac{-22}{17}+1\right)+11=11 \end{gathered}$$