Question

Answer 1

`[(2x-11):3+1].5=20`

`=> [(2x-11):3+1=20:5`

`=> (2x-11):3+1=4`

`=>(2x-11):3=4-1`

`=>(2x-11):3=3`

`=>2x-11=3.3`

`=>2x-11=9`

`=>2x=9+11`

`=>2x=20`

`=>x=20:2`

`=>x=10`

vậy `x=10` 

`@ M`

Answer 2

[(2.x-11):3+1].5=20

<=>(2.x-11):3+1=4

<=>(2.x-11):3=3

<=>2.x-11=9

<=>2.x=20

<=>x=10