(3x-2)/6 - 5 = [3- 2.(x-7)]/4
⇔ (3x -2)/6 - 30/6 = (3 -2x +14)/4
⇔ (3x -2 -30)/6 = (17 -2x)/4
⇔ (3x -32)/6 = (17-2x)/5
⇒ 6.(17-2x) = 5.(3x-32)
⇔ 102 -12x = 15x -160
⇔ -12x -15x = -160 -120
⇔ -27x = -280
⇔ x = -280 ÷ (-27)
⇔ x = 280/27
Vậy S= {280/27}