`( 5 + x )/( 3x - 6 ) - ( 2x - 3 )/( 2x - 4 ) = 1/2 `

Answer

`{5 + x}/{3x - 6} - {2x - 3}/{2x - 4} = 1/2` `(Đk: x \ne 2)`

`<=> {5 + x}/{3x - 6} - {2x - 3}/{2x - 4} - 1/2 = 0`

`<=> {5 + x}/{3 . (x - 2)} - {2x - 3}/{2 . (x - 2)} - 1/2 = 0`

`<=> {2 . (5 + x)}/{2 . 3 . (x - 2)} - {3 . (2x - 3)}/{2 . 3 . (x - 2)} - {1 . 3 . (x - 2)}/{2 . 3 . (x - 2)} = 0`

`<=> {10 + 2x}/{6 . (x - 2)} - {6x - 9}/{6 . (x - 2)} - {3x - 6}/{6 . (x - 2)} = 0`

`<=> (10 + 2x) - (6x - 9) - (3x - 6) = 0`

`<=> 10 + 2x - 6x + 9 - 3x + 6 = 0`

`<=> (2x - 6x - 3x) + (10 + 9 + 6) = 0`

`<=> -7x + 25 = 0`

`<=> -7x = 0 - 25`

`<=> -7x = -25`

`<=> x = (-25) : (-7)`

`<=> x = 25/7` (TMĐK)

Vậy `S = {25/7}`