Bonjour,
1: x+1,5=5,5
x = 5,5 - 1,5
x = 4
2: 8x=32
x = 32/8
x = 4
3: 4x+10=36
4x = 36 - 10
4x = 26
x = 26/4
x = 13/2
4: 1/2x+4=5
1/2x = 5 - 4
1/2x = 1
x = 2
5: 5x+3=7x-2
5x - 7x = - 2 - 3
- 2x = - 5
x = 5/2
6: 2(x-1)+4=5-4x
2x - 2 + 4 = 5 - 4x
2x + 4x = 5 + 2 - 4
6x = 3
x = 3/6
x = 1/2
7: 2x+9=6
2x = 6 - 9
2x = - 3
x = - 3/2.