`b) 8.(x -2) -2.(3x -4) = 0`
`⇔ 8x -16 -6x +8 = 0`
`⇔ 2x = 8`
`⇔ x = 4`
`Vậy` `S = {4}`
`c) 2x³.(2x -3) -x².(4x² -6x +2) = 0`
`⇔ 2x².x.(2x -3) -x².[2.(2x² -3x +1)] = 0`
`⇔ 2x².(2x² -3x) -2x².(2x² -3x +1) = 0`
`⇔ 2x².(2x² -3x -2x² +3x -1) = 0`
`⇔ 2x².(-1) = 0`
`⇔ x = 0`
`Vậy` `S = {0}`
`d) 10.(3x -2) -3.(5x +2) +5.(11 -4x) = 25`
`⇔ 30x -20 -15x -6 +55 -20x = 25`
`⇔ -5x +29 = 25`
`⇔ -5x = -4`
`⇔ x = 4/5`
`Vậy` `S = {4/5}`
