Đáp án:
Giải thích các bước giải:
a) `27/23-(-5)/21-4/23+16/21+1/2`
`=27/23+5/21+(-4)/23+16/21+1/2`
`=(27/23+(-4)/23)+(5/21+16/21)+1/2`
`=1+1+1/2`
`=2+1/2`
`=5/2`
b) `17/18*24/25*10/51`
`=(17.24.10)/(18.25.51)`
`=17/51*24/18*10/25`
`=1/3*4/3*2/5`
`=4/9*2/5`
`=8/45`
c) `8/9+1/9*2/9+1/9*7/9`
`=8/9+1/9.(2/9+7/9)`
`=8/9+1/9*1`
`=8/9+1/9`
`=1`