Réponses

2014-03-20T14:13:46+01:00
1. 3x+4=2x+9
3x-2x=9-4
x=5

2. 5x+2=9x+7
9x-5x=2-7
4x=-5
x=-5/4

3. 5-(x-3)=4x-(3x-8)
5-x+3=4x-3x+8
8-x=x+8
2x=8-8
x=0

4. 5(3x-1)-(1-2x)=3(5x-2)
15x-5-1+2x=15x-6
17x-6=15x-6
17x-15x=6-6
2x=0
x=0