a) 3 (x + 2) - x = 10; B) 4x + 3 (x - 7) = 5; д) 5-х=4 (x - 3); ж) 7- (2x + 3) = 9; и) 1/2 (x - 4) + 3x = 5; л) 5x - (1/2x + 9) = 18;

Решение:

1. a) \(3(x+2) - x = 10\)
   \(3x + 6 - x = 10\)
   \(2x = 10 - 6\)
   \(2x = 4\)
   \(x = 2\)
2. B) \(4x + 3(x-7) = 5\)
   \(4x + 3x - 21 = 5\)
   \(7x = 5 + 21\)
   \(7x = 26\)
   \(x = \frac{26}{7}\)
3. д) \(5 - x = 4(x-3)\)
   \(5 - x = 4x - 12\)
   \(5 + 12 = 4x + x\)
   \(17 = 5x\)
   \(x = \frac{17}{5}\)
4. ж) \(7 - (2x+3) = 9\)
   \(7 - 2x - 3 = 9\)
   \(4 - 2x = 9\)
   \(-2x = 9 - 4\)
   \(-2x = 5\)
   \(x = -\frac{5}{2}\)
5. и) \(\frac{1}{2}(x-4) + 3x = 5\)
   \(\frac{1}{2}x - 2 + 3x = 5\)
   \(\frac{1}{2}x + \frac{6}{2}x = 5 + 2\)
   \(\frac{7}{2}x = 7\)
   \(x = 7 \cdot \frac{2}{7}\)
   \(x = 2\)
6. л) \(5x - (\frac{1}{2}x + 9) = 18\)
   \(5x - \frac{1}{2}x - 9 = 18\)
   \(\frac{10}{2}x - \frac{1}{2}x = 18 + 9\)
   \(\frac{9}{2}x = 27\)
   \(x = 27 \cdot \frac{2}{9}\)
   \(x = 3 \cdot 2\)
   \(x = 6\)

Ответ: a) x = 2; B) x = 26/7; д) x = 17/5; ж) x = -5/2; и) x = 2; л) x = 6.