7 класс Линейные уравнения Решите уравнения: 1. 6(x-3) = 12 2. 14 = 7(x + 2) 3. 12x + 4 = 3(4x - 2) 4. 3x + (2x - 1) = 10 5. (3x - 2) - (x - 1) = 10 6. 2(x-1) - 4 = 6(x + 2) 7. 6x-3(x - 1) = 4 + 5x 8. 5x + 18 = 7x + 6(3x - 7) 9. 12 + 4(x-3) - 2x = (5-3x) + 9 10. 3x-7(3x-4) = 5(2x - 7)

Решим уравнения:

1. 6(x-3) = 12
   6x - 18 = 12
   6x = 12 + 18
   6x = 30
   x = 30 ∶ 6
   x = 5
   Ответ: x = 5
2. 14 = 7(x + 2)
   14 = 7x + 14
   7x = 14 - 14
   7x = 0
   x = 0 ∶ 7
   x = 0
   Ответ: x = 0
3. 12x + 4 = 3(4x - 2)
   12x + 4 = 12x - 6
   12x - 12x = -6 - 4
   0 = -10 - нет решений
   Ответ: нет решений
4. 3x + (2x - 1) = 10
   3x + 2x - 1 = 10
   5x = 10 + 1
   5x = 11
   x = 11/5
   x = 2.2
   Ответ: x = 2.2
5. (3x - 2) - (x - 1) = 10
   3x - 2 - x + 1 = 10
   2x - 1 = 10
   2x = 10 + 1
   2x = 11
   x = 11/2
   x = 5.5
   Ответ: x = 5.5
6. 2(x-1) - 4 = 6(x + 2)
   2x - 2 - 4 = 6x + 12
   2x - 6 = 6x + 12
   2x - 6x = 12 + 6
   -4x = 18
   x = -18/4
   x = -4.5
   Ответ: x = -4.5
7. 6x-3(x - 1) = 4 + 5x
   6x - 3x + 3 = 4 + 5x
   3x + 3 = 4 + 5x
   3x - 5x = 4 - 3
   -2x = 1
   x = -1/2
   x = -0.5
   Ответ: x = -0.5
8. 5x + 18 = 7x + 6(3x - 7)
   5x + 18 = 7x + 18x - 42
   5x + 18 = 25x - 42
   5x - 25x = -42 - 18
   -20x = -60
   x = -60 ∶ (-20)
   x = 3
   Ответ: x = 3
9. 12 + 4(x-3) - 2x = (5-3x) + 9
   12 + 4x - 12 - 2x = 5 - 3x + 9
   2x = 14 - 3x
   2x + 3x = 14
   5x = 14
   x = 14/5
   x = 2.8
   Ответ: x = 2.8
10. 3x-7(3x-4) = 5(2x - 7)
    3x - 21x + 28 = 10x - 35
    -18x + 28 = 10x - 35
    -18x - 10x = -35 - 28
    -28x = -63
    x = -63 ∶ (-28)
    x = 2.25
    Ответ: x = 2.25