Question

Bài 2: Tính

a, -3/4 + 2/7 + -1/4 + 3/5 + 5/7

b, -5/8 x -12/29 x 8/-10 x 5,8

Answer 1

\(a.\) \(\left(-\dfrac{3}{4}\right)+\dfrac{2}{7}+\left(-\dfrac{1}{4}\right)+\dfrac{3}{5}+\dfrac{5}{7}\)

= \(\left[\left(-\dfrac{3}{4}\right)+\left(-\dfrac{1}{4}\right)\right]+\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{3}{5}\)

= \(\left(-1\right)+1+\dfrac{3}{5}\)

= \(\dfrac{3}{5}\)