Question

Cộng các phân số :

\(\dfrac{2}{-3}+\dfrac{7}{18}\)

\(\dfrac{1}{2}+\dfrac{3}{-4}\)

Answer 1

\(a,\dfrac{2.6}{-3.6}+\dfrac{7}{18}=\dfrac{-12}{18}+\dfrac{7}{18}=\dfrac{5}{18}\\ b,\dfrac{1.2}{2.2}+\dfrac{-4}{3}=\dfrac{2}{4}.\dfrac{-4}{3}=\dfrac{-8}{12}=\dfrac{-2}{3}\)

Answer 2

Answer 3

a)2/-3+7/18=-12/18+7/18=(12/18-7/18)=5/18

b)1/2+3/-4=2/4+-3/4=(2/4-3/4)=-1/4