`|1-x| - 9/25 = (4/5)^2`

`|1-x| -9/25 = 16/25`

`|1-x| = 16/25 + 9/25`

`|1-x| = 1`

`TH1 :`

`1-x=1`

`x=1-1`

`x=0`

`TH2 :`

`1-x = -1`

`x = 1 - (-1)`

`x = 2`

Vậy `x in { 0;2}`

`3 xx (2-x)/4 = (3x-1)/3`

`(3 xx (2-x) )/4 = (3x-1)/3`

`(6- 3x)/4 = (3x-1)/3`

`(6-3x) . 3 = (3x-1) . 4`

`18 - 9x = 12x - 4`

`-9x -12x = -4 -18`

`-21x = -22`

`x = 22/21`

Vậy `x=22/21`

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`2 - x/4 = 3x - 1/3`

`4 xx (2 - x/4)   = 4 xx (3x-1/3)`

`8 - x = 12x - 4/3`

`-x  -12x = -4/3 - 8`

`-13x = -28/3`

`x = -28/3 : (-13)`

`x = 28/39`

Vậy `x=28/39`