1) 4х+12=5х-10
5х-4х=12+10
х=22
2) -2х+10+3х-12=4х+1
х-4х=1-10+12
-3х=3
х=-1
3)3х-3=2х+4
3х-2х=4+3
х=7
4)3х-15-2х-8=-5х+1
х+5х=1+23
6х=24
х=24:6
х=4
x^2-x+1=1