\(\dfrac{5}{6}< x< \dfrac{6}{7}\Leftrightarrow\dfrac{280}{336}< x< \dfrac{288}{336}\Leftrightarrow x\in\left\{\dfrac{281}{336};\dfrac{282}{336};\dfrac{283}{336};\dfrac{284}{336};\dfrac{285}{336};\dfrac{286}{336};\dfrac{287}{336}\right\}\)
Từ đó chọn ra 4 phân số