10. Решите уравнение: 1) 2x = 18 - x; 2) 7x + 3 = 30 - 2x; 3) 7 - 2x = 3x - 18; 4) 0,2x + 2,7 = 1,4 – 1,1x; 5) 5,4 - 1,5x = 0,3x - 3,6; 6) 3/8 x + 15 = 1/6 x + 10.

Решение:

1. \( 2x = 18 - x \)
   \( 2x + x = 18 \)
   \( 3x = 18 \)
   \( x = \frac{18}{3} \)
   \( x = 6 \)
2. \( 7x + 3 = 30 - 2x \)
   \( 7x + 2x = 30 - 3 \)
   \( 9x = 27 \)
   \( x = \frac{27}{9} \)
   \( x = 3 \)
3. \( 7 - 2x = 3x - 18 \)
   \( 7 + 18 = 3x + 2x \)
   \( 25 = 5x \)
   \( x = \frac{25}{5} \)
   \( x = 5 \)
4. \( 0,2x + 2,7 = 1,4 – 1,1x \)
   \( 0,2x + 1,1x = 1,4 - 2,7 \)
   \( 1,3x = -1,3 \)
   \( x = \frac{-1,3}{1,3} \)
   \( x = -1 \)
5. \( 5,4 - 1,5x = 0,3x - 3,6 \)
   \( 5,4 + 3,6 = 0,3x + 1,5x \)
   \( 9 = 1,8x \)
   \( x = \frac{9}{1,8} \)
   \( x = 5 \)
6. \( \frac{3}{8} x + 15 = \frac{1}{6} x + 10 \)
   \( \frac{3}{8} x - \frac{1}{6} x = 10 - 15 \)
   \( \frac{9 - 4}{24} x = -5 \)
   \( \frac{5}{24} x = -5 \)
   \( x = -5 \cdot \frac{24}{5} \)
   \( x = -24 \)

Ответ: 1) x = 6; 2) x = 3; 3) x = 5; 4) x = -1; 5) x = 5; 6) x = -24.