Ответ:

Пошаговое объяснение:

19)

0,4*(x - 0,3) = 0,3*(x - 0,4)

0,4x - 0,12 = 0,3x = 0,12

0,4x - 0,3x = -0,12 + 0,12

0,1x = 0

x = 0

==========

20)

5*x = 2*(x + 1,5)

5x = 2x + 3

5x - 2x = 3

3x = 3

x = 1

===========

21)

4,4*(x + 4) = 5,5*x

4,4x + 17,6 = 5,5x

5,5x - 4,4x = 17,6

1,1x = 17,6

x = 17,6 : 1,1

x = 16

======

22)

5*(x - 1) = 3*(x + 1)

5x - 5 = 3x + 3

5x - 3x = 3 + 5

2x = 8

x = 8 : 2

x = 4

========

23)

2*(2x - 1) = 1*(2x + 1)

4x - 2 = 2x + 1

4x - 2x = 1 + 2

2x = 3

x = 3 : 2

x = 1,5

=======

24)

9*(0,5x - 7) = 2*(2x + 1)

4,5x - 63 = 4x + 2

4,5x - 4x = 2 + 63

0,5x = 65

x = 65 : 0,5

x = 130

=========

25)

4*(0,2x - 1) = 3*(0,5x - 3)

0,8x - 4 = 1,5x - 9

1,5x - 0,8x = 9 - 4

0,7x = 5

x = 5 : 0,7

x = 7 1/7

==============

26)

6,5*(x - 2) = 1,5*(x - 3)

6,5x - 13 = 1,5x - 4,5

6,5x - 1,5x = 13 - 4,5

5x = 8,5

x = 8,5 : 5

x = 1,7

========

27)

5*(2x - 1,5) = 4*(3x - 4,5)

10x - 7,5 = 12x - 18

12x - 10x = 18 - 7,5

2x = 10,5

x = 10,5 : 2

x = 5,25

============

28)

6*(x - 2) = 2,5*x

6x - 12 = 2,5x

6x - 2,5x = 12

3,5x = 12

x = 12 : 3,5

x = 3 3/7

=============

29)

7*x = 1*(2x + 3)

7x = 2x + 3

7x - 2x = 3

5x = 3

x = 3 : 5

x = 0,6

==========

30)

3*(4x + 3) = 2*(1,5x - 4)

12x + 9 = 3x - 8

12x - 3x = -8 - 9

9x = -17

x = -17 : 9

x = -1 8/9

==========

31)

4*(0,75x - 1) = 1*(2,5x + 1)

3x - 4 = 2,5x + 1

3x - 2,5x = 1 + 4

0,5x = 5

x = 5 : 0,5

x = 10

=========

32)

7*(2x - 3) = 4*(x - 1,5)

14x - 21 = 4x - 6

14x - 4x = 21 - 6

10x = 15

x = 15:10

x = 1,5