Thực hiện phép tính: \(\lef...

C

- Hướng dẫn giải

Ta có:

$\left( { - \dfrac{3}{4} + \dfrac{2}{3}} \right):\dfrac{5}{{11}} + \left( { - \dfrac{1}{4} + \dfrac{1}{3}} \right):\dfrac{5}{{11}}$

$\begin{array}{l} = \left( { - \dfrac{3}{4} + \dfrac{2}{3}} \right).\dfrac{{11}}{5} + \left( { - \dfrac{1}{4} + \dfrac{1}{3}} \right).\dfrac{{11}}{5}\\ = \left( { - \dfrac{3}{4} + \dfrac{2}{3} - \dfrac{1}{4} + \dfrac{1}{3}} \right).\dfrac{{11}}{5}\\ = \left[ {\left( { - \dfrac{3}{4} - \dfrac{1}{4}} \right) + \left( {\dfrac{2}{3} + \dfrac{1}{3}} \right)} \right].\dfrac{{11}}{5}\\ = \left( { - 1 + 1} \right).\dfrac{{11}}{5}\\ = 0.\dfrac{{11}}{5}\\ = 0\end{array}$