giúp e Câu 4,6,7 vs ạ

`4) 11/12-(2/5+x)=2/3`

`=> 11/12-2/5-x=2/3`

`=> 31/60-x=2/3`

`=> x=31/60-2/3`

`=> x= -9/60`

`=> x=-3/20`

Vậy `x=-3/20`

`5) 3/4+1/4 :x=2/5`

`=> 1/4 :x=2/5-3/4`

`=> 1/4 :x=-7/20`

`=> x=1/4:(-7/20)`

`=> x=1/4 . (-20/7)`

`=> x=-5/7`

Vậy `x=-5/7`

`7) x+1/2=2^5 :2^3`

`=> x+1/2=2^2`

`=> x+1/2=4`

`=> x=4-1/2`

`=> x=7/2`

Vậy `x=7/2`