Х+9=0
х=-9
х-7=0
х=7
х+5=12
х=12-5
х=7
17+х=20
х=20-17
х=3
3х+7=4
3х=4-7
3х=-3
х=-1
2х-5=3
2х=3+5
2х=8
х=4
3х-1=8
3х=9
х=3
5-2х=3
2=2х
х=1
7+4х=5х
7=х
3х-12=-х
4х=12
х=3
2(х+5)-3=9
2х+10-3=9
2х+7=9
2х=2
х=1
х+2(х+7)=8
х+2х+14=8
3х=-6
х=-2
3(х-2)-5х=2
3х-6-5х=2
-2х=8
х=-4