Đáp án-Giải thích các bước giải:
QUY ĐỒNG:
`a)MSC:60`
`15/20=(15.3)/(20.3)=45/60`
`-10/15=(-10.4)/(15.4)=-40/60`
`41/60`
`b) MSC:60`
`17/20=(17.3)/(20.3)=51/60`
`13/15=(13.4)/(15.4)=52/60`
`1/-60=-1/60`
`c)MSC:6000`
`9/30=(9.200)/(30.200)=1800/6000`
`98/80=(98.75)/(80.75)=7350/6000`
`15/1000=(15.6)/(1000.6)=90/6000`
RÚT GỌN:
`a)`` (6.9-2.17)/(63.3-119)`
`=(54-34)/(189-119)`
`=20/70`
`=2/7`
`b) ``(2929-101)/(2.1919+404)`
`=(29.101-101)/(2.101.19+101.4)`
`=(101(29-1))/(101(2.19+4))`
`=28/42`
`=2/3`
`c)` `(3.13-13.18)/(15.40-80)`
`=(13(3-18))/(15.40-40.2)`
`=(13.(-15))/(40(15-2))`
`=(13.(-15))/(40.13)`
`=-15/40=-3/8`
`d)``(18.34+(-18).124)/(-36.17+9.(-52))`
`=(18.2.17+(-18).2.62)/(-36.7+9.4.(-13))`
`=(36.(17-62))/(36(-7-13))`
`=-45/-20=9/4`
