1.
4(x+5)-(x+8)=4x-7
4x+20-x-8-4x+7=0
20-x-8+7=0
19-x=0
x=-19/-1
x=19
2.
2(-x-3)-7(x+4)=12x-3-5
-2x-6-7x-28-12x+3+5=0
-21x-26=0
-21x=26
x=-26/21
3.
18x-13-(5+7)=15x-8
17x-13-12-15x+8=0
3x=17
x=17/3
4.
(x+4)(7-5)=2x-8
(x+4)*2=2x-8
2x+8-2x+8=0
+16=0 Il n'ya aucune solution possible!!!
5.
12x+13-(4x-5)=13+4x
12x+13-4x+5-13-4x=0
4x+5=0
x=-5/4
Voilà!
