РЕШИТЕ УРАВНЕНИЯ х = - 21;
2. 20х = -5;
3. 8х + 5 = 0;
4. 3х – 7 = 2;
5. 11 – 4х = 2х;
6. 8х – 2 = 7 + 2х;
7. 3х + (4 – 6х) = 18;
8. 6х – (2х + 5) = - 4;
9. 6 – 2(3х – 9) = - 4х;
10. 5 (2х +2) – 5х = 13;
11. (х – 9)(х+13) = 0;
12. (4х+3)(2х–1) = 0.

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Пошаговое объяснение:

1. – 3х = - 21;

x = -21:(-3)

x = 7

2. 20х = -5;

x = -5:20

x = -0,25

3. 8х + 5 = 0;

8x = -5

x = -5:8

x = -0,625

4. 3х – 7 = 2;

3x = 2 + 7

3x = 9

x = 9:3

x = 3

5. 11 – 4х = 2х;

2x+4x = 11

6x = 11

x = 11 : 6

x = 1 5/6

6. 8х – 2 = 7 + 2х;

8x - 2x = 7+2

6x = 9

x = 9 : 6

x = 1,5

7. 3х + (4 – 6х) = 18;

3x + 4 - 6x = 18

-3x + 4 = 18

3x = -18+4

3x = -14

x = -14:3

x = -4 2/3

8. 6х – (2х + 5) = - 4;

6x - 2x - 5 = -4

4x - 5 = -4

4x = -4+5

4x = 1

x = 1:4

x = 0,25

9. 6 – 2(3х – 9) = - 4х;

6 - 6x + 18 = -4x

24 - 6x = -4x

6x - 4x = 24

2x = 24

x = 24 : 2

x = 12

10. 5 (2х +2) – 5х = 13;

10x + 10 - 5x = 13

5x + 10 = 13

5x = 13 - 10

5x = 3

x = 3:5

x = 0,6

11. (х – 9)(х+13) = 0;

x - 9 = 0 или x + 13 = 0

x = 9              x = -13

12. (4х+3)(2х–1) = 0.

4x + 3 = 0 или 2x - 1 = 0

4x = -3              2x = 1

x = -3:4              x = 1:2

x = -0,75            x = 0,5