\(\displaystyle 4{1 \over 3}.\left( {{1 \over 6} - {1 \over 2}} \right) \le x \)\(\displaystyle\le {2 \over 3}.\left( {{1 \over 3} - {1 \over 2} - {3 \over 4}} \right)\)
\(\displaystyle \Rightarrow {{13} \over 3}.\left( {{1 \over 6} - {3 \over 6}} \right) \le x \)\(\displaystyle \le {2 \over 3}.\left( {{4 \over {12}} - {6 \over {12}} - {9 \over {12}}} \right) \)
\(\displaystyle \Rightarrow {{ - 13} \over 9} \le x \le {{ - 11} \over {18}} \)
Mà \(x\) là số nguyên \(\displaystyle \Rightarrow x = - 1. \)
