1) 6 + 5(2 - 4x) = 3(1 - 3x)
⇔ 6 + 10 - 20x = 3 - 9x
⇔ -20x + 9x = 3 - 6 - 10
⇔ -11x = -13
⇔ x = `\frac{13}{11}`
Vậy phương trình có S = {`\frac{13}{11}`}
2) 3(3x - 1) + 2 = 5(1 - 2x) - 1
⇔ 9x - 3 + 2 = 5 - 10x - 1
⇔ 9x + 10x = 5 - 1 + 3 - 2
⇔ 19x = 5
⇔ x = `\frac{5}{19}`
Vậy...
3) 2(x + 1) - 3(x - 1) = 36 - 9(x + 3)
⇔ 2x + 2 - 3x + 3 = 36 - 9x - 27
⇔ 2x - 3x + 9x = 36 - 27 - 2 - 3
⇔ 8x = 4
⇔ x = `\frac{1}{2}`
Vậy...
4) 5(2x - 3) - 4(5x - 17) = 19 - 2(x + 11)
⇔ 10x - 15 - 20x + 68 = 19 - 2x - 22
⇔ 10x - 20x + 2x = 19 - 22 + 15 - 68
⇔ -8x = -56
⇔ x = -7
Vậy...
5) 4(x + 3) - 7x + 17 = 8(5x - 1) + 166
⇔ 4x + 12 - 7x + 17 = 40x - 8 + 166
⇔ 4x - 7x - 40x = -8 + 166 - 12 - 17
⇔ -43x = 129
⇔ x = -3
Vậy...
6) 17 - 14(x + 1) = 13 - 4(x + 1) - 5(x - 3)
⇔ 17 - 14x - 14 = 13 - 4x - 4 - 5x + 15
⇔ -14x + 4x + 5x = 13 - 4 + 15 - 17 + 14
⇔ -5x = 21
⇔ x = `\frac{-21}{5}`
Vậy...
