Réponse:
1. 7x +12= 3x +13
7x-3x +12= 3x-3x +13
4x +12 -12= 13-12
4x = 1
4x/4 =1/4
x=0,25
2. 8x+5 = 5x+12
8x-5x+5 = 5x-5x+12
3x+5-5 = 12-5
3x = 7
3x/3 = 7/3
x=2,3333
3. 2x+8=11x+2
2x-11x+8-8=11x-11x+2-8
-9x=-6
-9x/-9=-6/-9
x=0,66666
4. 10x+5=3x+6
10x-3x+5-5=3x-3x+6-5
7x=1
7x/7=1/7
x=0,142
5. 11x+1=9x+9
11x-9x+1-1=9x-9x+9-1
2x=8
2x/2=8/2
x=4
6. 2x+10=5x+9
2x-5x+10-10=5x-5x+9-10
-3x=-1
-3x/-3=-1/-3
x=0,3333
