Bonsoir,
7 x = -28
x= -28/7 = -4
- 3x = -2,1
x= -2,1/-3 = 2,1/3
– 7x = -18
x= -18/-7 = 18/7
4x – 12 = 0
4x= 12
x= 12/4 = 3
3x – 1=0
3x=1
x= 1/3
2 x+8 = 0
2x= -8
x= -8/2 = -4
2 - 3x = 0
2 = 3x
x= 2/3
2x -2=2
2x= 2+2
2x= 4
x= 4/2 = 2
3y-10 = 11
3y = 11+10
3y = 21
y = 21/3 = 7
1+ 5z = -39
5z = -39-1
5z = -40
z = -40/5 = -8
2 + 3a = 9
3a = 9-2
3a = 7
a= 7/3