\(\dfrac{-3}{8}+\dfrac{12}{25}+\dfrac{5}{-8}+\dfrac{2}{-5}+\dfrac{13}{25}\)
\(=\dfrac{-3}{8}+\dfrac{12}{25}+\dfrac{-5}{8}+\dfrac{-2}{5}+\dfrac{12}{25}\)
\(=\left(\dfrac{-3}{8}+\dfrac{-5}{8}\right)+\left(\dfrac{12}{25}+\dfrac{12}{25}+-\dfrac{2}{5}\right)\)
Còn lại bn tự tính nhé!
\(\dfrac{-3}{8}\) + \(\dfrac{12}{25}\) + \(\dfrac{5}{-8}\) + \(\dfrac{2}{-5}+\dfrac{13}{25}\)
= \(\left(\dfrac{-3}{8}+\dfrac{5}{-8}\right)+\left(\dfrac{12}{25}+\dfrac{13}{25}\right)+\dfrac{2}{-5}\)
= \(\left(\dfrac{-3}{8}+\dfrac{-5}{8}\right)+1+\dfrac{-2}{5}\)
= 1 + 1 + \(\dfrac{-2}{5}\)
= \(\dfrac{8}{5}\)
Ta chuyển tất cả những ph/số có MS là số âm thành số dương.
Ta có : -3/8 + 12/25 + -5/8 + -2/5 + 13/25
= (-3/8 + -5/8) + ( 12/25 + 13/25) + -2/5
= -8/8 + 25/25 + -2/5
= -1 + 1 + -2/5
= 0 + -2/5
= -2/5