Đáp án+Giải thích các bước giải:
Câu 1:
`2/3+1/(3).((-4)/9+5/6):7/12`
`=2/3+1/(3).((-8)/18+15/18):7/12`
`=2/3+1/(3).((-8+15)/18):7/12`
`=2/3+1/3.(7)/18:7/12`
`=2/3+1/3.(7)/18.(12)/7`
`=2/3+(1.7.12)/(3.18.7)`
`=2/3+(1.12)/(3.18)`
`=2/3+(2.3.2)/(3.2.9)`
`=2/3+2/9`
`=6/9+2/9`
`=8/9`
Câu 2:
`0,25.1(1)/(3).50%:7/6+3/2`
`=1/4.(4)/3.(1)/2:7/6+3/2`
`=1/3.(1)/2:7/6+3/2`
`=1/6.(6)/7+3/2`
`=1/7+3/2`
`=2/14+21/14`
`=23/14`
