Question

ПОЖАЛУЙСТА ПОМОГИТЕ!! ДАЮ 20 БАЛЛОВ!!​ НАДО С ПРОВЕРКОЙ!!

Answer 1

1) 2x+13 = 22+3x

2x-3x = 22-13

-x = 9

x = -9

Проверка:

2x+13 = 2·(-9)+13 = -18+13 = -5

22+3x = 22+3·(-9) = 22-27 = -5

-5 = -5

2) 3x-(10-9x) = 22x

3x-10+9x = 22x

12x-10 = 22x

12x-22x = 10

-10x = 10

x = -1

Проверка:

3x-(10-9x) = 3·(-1)-(10-9·(-1)) = -3-(10+9) = -3-19 = -22

22x = 22·(-1) = -22

3) 21x+45 = 15+14x

21x-14x = 15-45

7x = -30

x = -30/7

Проверка:

21x+45 = 21·(-30/7)+45 = -3·30+45 = -90+45 = -45

15+14x = 15+14·(-30/7) = 15+2·(-30) = 15-60 = -45

-45 = -45

4) 13x+40 = 2x+7

13x-2x = 7-40

11x = -33

x = -3

Проверка:

13x+40 = 13·(-3)+40 = -39+40 = 1

2x+7 = 2·(-3)+7 = -6+7 = 1

1 = 1

5) 25-(7-2x) = 5x

25-7+2x = 5x

18+2x = 5x

2x-5x = -18

-3x = -18

x = 6

Проверка:

25-(7-2x) = 25-(7-2·6) = 25-(7-12) = 25-(-5) = 25+5 = 30

5x = 5·6 = 30

30 = 30

6) 5-3x = 2x-8

-3x-2x = -8-5

-5x = -13

x = 13/5

Проверка:

5-3·13/5 = 5-39/5 = 5-7 4/5 = -2 4/5

2x-8 = 2·13/5-8 = 26/5-8 = 5 1/5-8 = -2 4/5

-2 4/5 = -2 4/5

7) 2x+40 = x+14

2x-x = 14-40

x = -26

Проверка:

2x+40 = 2·(-36)+40 = -52+40 = -12

x+14 = -26+14 = -12

-12 = -12

8) 14x+5x = 4x+3

19x = 4x+3

19x-4x = 3

15x = 3

x = 3/15 = 1/5

Проверка:

14x+5x = 14·1/5+5·1/5 = 14/5+5/5 = 19/5

4x+3 = 4·1/5+3 = 4/5+15/5 = 19/5

19/5 = 19/5

9) -15x+31 = -7+4x

-15x-4x = -7-31

-19x = -38

x = 2

Проверка:

-15x+31 = -15·2+31 = -30+31 = 1

-7+4x = -7+4·2 = -7+8 = 1

1 = 1

10) 3x-12 = 8x+13

3x-8x = 13+12

-5x = 25

x = -5

Проверка:

3x-12 = 3·(-5)-12 = -15-12 = -27

8x+13 = 8·(-5)+13 = -40+13 = -27

-27 = -27