Question

Tính: 

a)\(\dfrac{6}{18}\)+\(\dfrac{-14}{21}\)                                                    b)\(\dfrac{3}{5}\)-\(\dfrac{-1}{2}\)

c)\(\dfrac{2}{7}\):\(\dfrac{3}{4}\)                                                           d) \(\dfrac{-28}{33}\).\(\dfrac{-3}{4}\)

Answer 1

a) `6/18+ (-14)/21 = 1/3 - 2/3=-1/3`

b) `3/5 - (-1/2) = 3/5+1/2=11/10`

c) `2/7 : 3/4 = 2/7 . 4/3 = 8/21`

d) `(-28)/33 . (-3)/4 = 28/33 . 3/4=7/11`

Answer 2

a) \(\dfrac{6}{18}+\dfrac{-14}{21}=\dfrac{1}{3}-\dfrac{2}{3}=\dfrac{-1}{3}\)

b) \(\dfrac{3}{5}-\dfrac{-1}{2}=\dfrac{3}{5}+\dfrac{1}{2}=\dfrac{6}{10}+\dfrac{5}{10}=\dfrac{11}{10}\)

c) \(\dfrac{2}{7}:\dfrac{3}{4}=\dfrac{2}{7}\cdot\dfrac{4}{3}=\dfrac{8}{21}\)

d) \(\dfrac{-28}{33}\cdot\dfrac{-3}{4}=\dfrac{28}{4}\cdot\dfrac{3}{33}=7\cdot\dfrac{1}{11}=\dfrac{7}{11}\)