Решение линейных уравнений:

1) 7x = 1

$$x = \frac{1}{7}$$

2) 5x - 3 = x - 19

$$5x - x = -19 + 3$$

$$4x = -16$$

$$x = -4$$

3) 4x + 2 = 5x

$$5x - 4x = 2$$

$$x = 2$$

4) 4 - 5x = 5

$$-5x = 5 - 4$$

$$-5x = 1$$

$$x = -\frac{1}{5}$$

5) -9x + 5 = 6x - 4

$$6x + 9x = 5 + 4$$

$$15x = 9$$

$$x = \frac{9}{15} = \frac{3}{5}$$

6) -5x - 1 = 2x + 2

$$-5x - 2x = 2 + 1$$

$$-7x = 3$$

$$x = -\frac{3}{7}$$

7) 5x - 9 = 3x + 1

$$5x - 3x = 1 + 9$$

$$2x = 10$$

$$x = 5$$

8) 11x = 4x

$$11x - 4x = 0$$

$$7x = 0$$

$$x = 0$$

9) -2y + 14 = 8y - 6

$$8y + 2y = 14 + 6$$

$$10y = 20$$

$$y = 2$$

10) 0,3x + 0,15 = 0

$$0,3x = -0,15$$

$$x = -\frac{0,15}{0,3} = -\frac{1}{2}$$

$$x = -0,5$$

11) 0,8x + 16 = 20 + 0,7x

$$0,8x - 0,7x = 20 - 16$$

$$0,1x = 4$$

$$x = 40$$

12) 8,9x + 17,54 = 5,4

$$8,9x = 5,4 - 17,54$$

$$8,9x = -12,14$$

$$x = -\frac{12,14}{8,9} = -1,36404494382$$

13) 6(x - 1) = 12

$$6x - 6 = 12$$

$$6x = 12 + 6$$

$$6x = 18$$

$$x = 3$$

14) 4(x - 5) = 12 - x

$$4x - 20 = 12 - x$$

$$4x + x = 12 + 20$$

$$5x = 32$$

$$x = \frac{32}{5} = 6,4$$

15) 3(2 - x) = (6 - 5x) + 2x

$$6 - 3x = 6 - 5x + 2x$$

$$6 - 3x = 6 - 3x$$

$$0 = 0$$

x - любое число.

16) 7(x - 2) = 42

$$7x - 14 = 42$$

$$7x = 42 + 14$$

$$7x = 56$$

$$x = 8$$