4)\(\dfrac{-7}{12}+\dfrac{11}{20}-\dfrac{8}{15}=\dfrac{-1}{30}-\dfrac{8}{15}=\dfrac{-17}{30}\)
5)3/5-2/3+16/15=-1/15+16/15=1
6)-2/7.3/11+-2/7.8/11+4/7=-2/7.(3/11+8/11)+4/7=-2/7.1+4/7=-2/7+4/7=2/7
10)9/11+(-2/5+1/6):11/30=9/11+-7/30:11/30=9/11+-7/11=2/11
11)2/3+4/3:(-8/9)=2/3+4/3:-8/9=2/3+-3/2=-5/6
12)4/30.2/5+2/15.4/5+2/15.(-1/5)=4/30.2/5+2/15.4/5+2/15.-1/5=2/15.(2/5+4/5+-1/5).4/30=2/15.1.4/30=2/15.4/30=4/225
16)\(\left(0,7-\dfrac{1}{5}\right):\dfrac{5}{2^3}=\left(\dfrac{7}{10}-\dfrac{1}{5}\right):\dfrac{5}{2^3}=\dfrac{1}{2}:\dfrac{5}{2^3}=\dfrac{4}{5}\)
BẠN THAM KHẢO NHA
(GHI CHÚ:"9/11" LÀ \(\dfrac{9}{11}\)NHA.)