Вариант 1: 1. 3x - 12 = 8 - 2x 2. -7x - 2 = 4x + 9 3. 2(7x + 11) - 5x = 5x 4. 2x - 3(x - 3) = 12 5. 6 - 5(4x - 1) = 3

Решение:

1. \( 3x - 12 = 8 - 2x \)
   \( 3x + 2x = 8 + 12 \)
   \( 5x = 20 \)
   \( x = \frac{20}{5} \)
   \( x = 4 \)
2. \( -7x - 2 = 4x + 9 \)
   \( -7x - 4x = 9 + 2 \)
   \( -11x = 11 \)
   \( x = \frac{11}{-11} \)
   \( x = -1 \)
3. \( 2(7x + 11) - 5x = 5x \)
   \( 14x + 22 - 5x = 5x \)
   \( 9x + 22 = 5x \)
   \( 9x - 5x = -22 \)
   \( 4x = -22 \)
   \( x = \frac{-22}{4} \)
   \( x = -5.5 \)
4. \( 2x - 3(x - 3) = 12 \)
   \( 2x - 3x + 9 = 12 \)
   \( -x + 9 = 12 \)
   \( -x = 12 - 9 \)
   \( -x = 3 \)
   \( x = -3 \)
5. \( 6 - 5(4x - 1) = 3 \)
   \( 6 - 20x + 5 = 3 \)
   \( 11 - 20x = 3 \)
   \( -20x = 3 - 11 \)
   \( -20x = -8 \)
   \( x = \frac{-8}{-20} \)
   \( x = 0.4 \)

Ответ: 1. x = 4; 2. x = -1; 3. x = -5.5; 4. x = -3; 5. x = 0.4