1. Rút gọn nếu có:
a) \(\dfrac{6}{12}\) - \(\dfrac{-14}{39}\)
b) \(\dfrac{7}{21}\) - \(\dfrac{9}{-36}\)
c) \(\dfrac{-3}{21}\) - \(\dfrac{6}{42}\)
d) \(\dfrac{1}{6}\) - \(\dfrac{2}{5}\)
e) ( - 2 ) - \(\dfrac{-5}{8}\)
f) \(\dfrac{1}{-8}\) - \(\dfrac{-5}{9}\)
g) \(\dfrac{-3}{29}\) - \(\dfrac{16}{58}\)
i) \(\dfrac{2}{21}\) - \(\dfrac{1}{28}\)
k) \(\dfrac{18}{24}\) - \(\dfrac{35}{-10}\)
Giúp mk với mn, mk cần gấp ạ!!
a: \(\dfrac{6}{12}-\dfrac{-14}{39}=\dfrac{1}{2}+\dfrac{14}{39}=\dfrac{39}{78}+\dfrac{28}{78}=\dfrac{67}{78}\)
b: \(\dfrac{7}{21}-\dfrac{9}{-36}=\dfrac{1}{3}+\dfrac{1}{4}=\dfrac{4}{12}+\dfrac{3}{12}=\dfrac{7}{12}\)
c: \(\dfrac{-3}{21}-\dfrac{6}{42}=\dfrac{-1}{7}-\dfrac{1}{7}=-\dfrac{2}{7}\)
d: \(\dfrac{1}{6}-\dfrac{2}{5}=\dfrac{5}{30}-\dfrac{12}{30}=-\dfrac{7}{30}\)
e: \(\left(-2\right)-\dfrac{-5}{8}=-2+\dfrac{5}{8}=\dfrac{-16+5}{8}=-\dfrac{11}{8}\)
f: \(\dfrac{1}{-8}-\dfrac{-5}{9}=\dfrac{-1}{8}+\dfrac{5}{9}=\dfrac{-9+40}{72}=\dfrac{31}{72}\)
g: \(\dfrac{-3}{29}-\dfrac{16}{58}=-\dfrac{3}{29}-\dfrac{8}{29}=-\dfrac{11}{29}\)
i: \(\dfrac{2}{21}-\dfrac{1}{28}=\dfrac{8}{84}-\dfrac{3}{84}=\dfrac{5}{84}\)
k: \(\dfrac{18}{24}-\dfrac{35}{-10}=\dfrac{3}{4}+\dfrac{7}{2}=\dfrac{3}{4}+\dfrac{14}{4}=\dfrac{17}{4}\)
chia nửa đi!
rồi tui làm cho