857.
1)2х+17=22+3х
2х-3х=22-17
-х=5
х=-5
2)18+3х=х+14
3х-х=14-18
2х=-4
х=-2
3)25-4х=12-5х
-4х+5х=12-25
х=-13
4)13х+27=16х+4.5
13х-16х=4.5-27
-3х=-22.5
х=-7.5
5)21х+45=17+14х
21х-14х=17-45
7х=-28
х=-28/7
х=-4
6)13х+70=2х+15
13х-2х=15-70
11х=-55
х=-55/11
х=-5
Остальное по аналогии