Tìm số nguyên x, biết (-8/13 + 7/17) + 21/13 nhỏ hơn hoặc bằng x

* Hướng dẫn giải

$\begin{array}{l}\left(\frac{-8}{13}+\frac{7}{17}\right)+\frac{21}{13}\le x\le \left(\frac{-9}{14}+3\right)+\frac{5}{-14}\\ \Rightarrow \frac{-8}{13}+\frac{7}{17}+\frac{21}{13}\le x\le \frac{-9}{14}+3+\frac{-5}{14}\\ \Rightarrow \left(\frac{-8}{13}+\frac{21}{13}\right)+\frac{7}{17}\le x\le \left(\frac{-9}{14}+\frac{-5}{14}\right)+3\\ \Rightarrow 1+\frac{7}{17}\le x\le -1+3\\ \Rightarrow \frac{24}{17}\le x\le 2\\ \Rightarrow 1,\mathrm{411...}\le x\le 2\\ \Rightarrow x=2\end{array}$