(2 phần 3 x + 1 phần 3 )^ 2 = 4 phần 9 giúp mình vs

Đáp án:

 `(2/3x+1/3)^2=4/9`

TH1: `(2/3x+1/3)^2=(2/3)^2`

`⇔2/3x+1/3=2/3`

`⇔2/3x=1/3`

`⇔x=1/3.(3/2)`

`⇔x=1/2`

TH2: `(2/3x+1/3)^2=(-2/3)^2`

`⇔2/3x+1/3=-2/3`

`⇔2/3x=-1`

`⇔x=-1.3/2`

`⇔x=-3/2`

vậy `x∈{1/2;-3/2}`