Răspuns :
3+12x=7
12x=4
X=1/3
3-6x=2
-6x=-1
X=1/2
4x+6=7
4x=1
X=1/4
20+8x=-16
8x=-36
X=2/9
15x-20=-23
15x=3
X=1/5
20x-35=-43
20x=8
X=2/5
12x=4
X=1/3
3-6x=2
-6x=-1
X=1/2
4x+6=7
4x=1
X=1/4
20+8x=-16
8x=-36
X=2/9
15x-20=-23
15x=3
X=1/5
20x-35=-43
20x=8
X=2/5