1. 6 + 5(2 – 4x) = 3(1 – 3x) 2 . 3(3x – 1) + 2 = 5(1 – 2x) – 1 3. 2(x + 1) – 3(x – 1) = 36 – 9(x + 3) 4. 5(2x – 3) – 4(5x – 17) = 19 – 2(x + 11) 5.

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…

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