bonsoir j'aurais besoin d'aide s^vp

Bonsoir,

1)

3x= 7

x= 7/3

2)

6-4 = x

x= 2

3)

3x+21 = 9

3x= 9-21

3x = -12

x= -12/3 = -4

4)

x=8

1)

3x-x =-1 -7

2x= -8

x = -8/4 = -2

2)

6-14 = x+x

-8 = 2x

x= -8/2 = -4

3)

3x+21 = 4x+9

21-9 = 4x-3x

12 = x

4)

2x -8 = 7x-2

-8+2 = 7x-2x

-6 = 5x

x= -6/5

3)