3 х - 6 = 4 х

6 х-21=9

3 х-4+2 х=6+2 х

5 х+15=10

4-2 у=у-5

50-7 у-16=3 у-18

3 х - 6 = 4 х

4x - 3x = - 6

x = - 6

6 х-21=9

6x = 9 + 21

6x = 30

x = 30 : 6

x = 5

3 х-4+2 х=6+2 х

5x - 4 = 6 + 2x

5x - 2x = 6 + 4

3x = 10

x = 10 : 3

x = 3 1/3

5 х+15=10

5x = 10 - 15

5x = - 5

x = - 5 : 5

x = - 1

4-2 у=у-5

y + 2y = 5 + 4

3y = 9

y = 9 : 3

y = 3

50-7 у-16=3 у-18

34 - 7y = 3y - 18

3y + 7y = 34 + 18

10y = 52

y = 52 : 10

y = 5,2