`3/8 xx (-5)/7 + (-5/7) xx 5/8`
`= -5/7 xx (3/8+5/8)`
`=-5/7 xx 8/8`
`=-5/7 xx 1`
`=-5/7`
có vẻ hơi sai lớp vs môn nhỉ:<
\(\dfrac{3}{8}.\dfrac{-5}{7}+\left(\dfrac{-5}{7}\right).\dfrac{5}{8}=\dfrac{-5}{7}.\left(\dfrac{3}{8}+\dfrac{5}{8}\right)=\dfrac{-5}{7}.1=\dfrac{-5}{7}\)
38 ×−57+(−57)×5838 ×-57+(-57)×58
=−57×(38+58)=-57×(38+58)
=−57×88=-57×88
=−57×1=-57×1
=−57