Question

|x+2|-1=0

Answer 1

`|x+2|-1=0`

`@TH1: x+2 >= 0<=>x >= -2=>|x+2|=x+2`

    `=>x+2-1=0`

`<=>x=-1` (t/m)

`@TH2: x+2 < 0<=>x < -2=>|x+2|=-x-2`

    `=>-x-2-1=0`

`<=>x=-3` (t/m)

Vậy `S={-1;-3}`

Answer 2

`|x + 2| = x + 2` khi `x >= -2`.

`= -x - 2` khi `x < 2`.

`TH_1: x >=-2 => x + 2 - 1 = 0 => x +1 = 0 => x = -1 => tm`

`TH_2:x < 2 => -x - 2 - 1 = 0 => -x - 3 = 0 => x = -3 => tm`.

Vậy `x = -1, -3`.

Answer 3