Question

Tính Nhanh

3/-4 + -3/-4 + 2/5 + -1/2 + 3/5

Answer 1

\(=\left(-\dfrac{3}{4}+\dfrac{3}{4}\right)+\left(\dfrac{2}{5}+\dfrac{3}{5}\right)-\dfrac{1}{2}=1-\dfrac{1}{2}=\dfrac{1}{2}\)

Answer 2

\(\dfrac{3}{-4}+\dfrac{-3}{-4}+\dfrac{2}{5}+\dfrac{-1}{2}+\dfrac{3}{5}\\ =\left(\dfrac{-3}{4}+\dfrac{3}{4}\right)+\left(\dfrac{2}{5}+\dfrac{3}{5}\right)-\dfrac{1}{2}\\ =0+1-\dfrac{1}{2}\\ =1-\dfrac{1}{2}\\ =\dfrac{1}{2}\)