Решение уравнений:

1. $$7x = -30 + 2x$$
   $$7x - 2x = -30$$
   $$5x = -30$$
   $$x = \frac{-30}{5}$$
   $$\textbf{x = -6}$$
2. $$16 - 18x = -25x - 12$$
   $$-18x + 25x = -12 - 16$$
   $$7x = -28$$
   $$x = \frac{-28}{7}$$
   $$\textbf{x = -4}$$
3. $$-17x + 20 = 7x - 28$$
   $$-17x - 7x = -28 - 20$$
   $$-24x = -48$$
   $$x = \frac{-48}{-24}$$
   $$\textbf{x = 2}$$
4. $$20 - 2x = 27 + x$$
   $$-2x - x = 27 - 20$$
   $$-3x = 7$$
   $$x = \frac{7}{-3}$$
   $$\textbf{x = -\frac{7}{3}}$$
5. $$0,2x + 4,3 = 0,4x - 6,5$$
   $$0,2x - 0,4x = -6,5 - 4,3$$
   $$-0,2x = -10,8$$
   $$x = \frac{-10,8}{-0,2}$$
   $$\textbf{x = 54}$$
6. $$0,6x + 100 = 0,9x + 1$$
   $$0,6x - 0,9x = 1 - 100$$
   $$-0,3x = -99$$
   $$x = \frac{-99}{-0,3}$$
   $$\textbf{x = 330}$$
7. $$\frac{-9}{14}x + 18 = \frac{-2}{3}x + 17$$
   $$\frac{-9}{14}x + \frac{2}{3}x = 17 - 18$$
   $$\frac{-27}{42}x + \frac{28}{42}x = -1$$
   $$\frac{1}{42}x = -1$$
   $$x = -1 \cdot 42$$
   $$\textbf{x = -42}$$
8. $$\frac{-8}{15}x - 11 = \frac{4}{9}x + 11$$
   $$\frac{-8}{15}x - \frac{4}{9}x = 11 + 11$$
   $$\frac{-24}{45}x - \frac{20}{45}x = 22$$
   $$\frac{-44}{45}x = 22$$
   $$x = 22 : \frac{-44}{45}$$
   $$x = 22 \cdot \frac{45}{-44}$$
   $$x = \frac{45}{-2}$$
   $$\textbf{x = -22,5}$$