Ответ:

Пошаговое объяснение:

a)

x + 2x = 45

3x = 45

x = 45:3

x = 15

б)

3x + x = 14

4x = 14

x = 14 : 4

x = 3,5

в)

x + 2x + 3x = 30

6x = 30

x = 30 : 6

x = 5

a)

x +(x+4) = 22

x + x + 4 = 22

2x + 4 = 22

2x= 22 - 4

2x = 18

x = 18 : 2

x = 9

б)

(x - 7) + x = 33

x - 7 + x = 33

2x - 7 = 33

2x = 33 + 7

2x = 40

x = 40 : 2

x = 20

в)

x + (x - 1) = 40

x + x - 1 = 40

2x - 1 = 40

2x = 40 + 1

2x = 41

x = 41 : 2

x = 20,5