2/11.-5/4+-9/11.5/4+7/4

Đáp án:

 `1/2`

Giải thích các bước giải:

$\dfrac{2}{11}.\dfrac{-5}{4}+\dfrac{-9}{11}.\dfrac{5}{4}+\dfrac{7}{4}\\ =\dfrac{-2}{11}.\dfrac{5}{4}+\dfrac{-9}{11}.\dfrac{5}{4}+\dfrac{7}{4}\\ =\dfrac{5}{4}\left(\dfrac{-2}{11}+\dfrac{-9}{11}\right)+\dfrac{7}{4}\\ =\dfrac{5}{4}.\left(-1\right)+\dfrac{7}{4}\\ =\dfrac{-5}{2}+\dfrac{7}{4}\\ =\dfrac{2}{4}\\ =\dfrac{1}{2}$

`#hung`