Đáp án + Giải thích các bước giải:
Bài `1` :
`a)` `(5/7-7/5)-[1/2-(-2/7-1/10)]`
`=(25/35-49/35)-(1/2+2/7+1/10)`
`=-24/35-(35/70+20/70+7/70)`
`=-24/35-62/70=-48/70-62/70=-110/70=-11/7`
`b)` `(-1/3+5/6)*11-7=(-2/6+5/6)*11-7`
`=3/6*11-7`
`=1/2*11-7`
`=11/2-7=11/2-14/2=-3/2`
`c)` `(-1/3)^2:1/6-2(-1/2)^3`
`=1/9:1/6-2(-1/8)`
`=1/9*6-(-1/4)`
`=2/3+1/4`
`=8/12+3/12=11/12`.