2,5х+4=9
2,5х=9-4
2,5х=5
х=5/2.5
х=2
1.7х-2.1=3
1,7х=3+2.1
1.7х=5.1
х=5.1/1.7
х=3
0.5-17=40.52
что принята за х?
0.4х+0.24х-0.26=0.764
0.4х+0.24х=0.764-0.26
0.64х=0.736
х=0.736/0.64
х=1.15
..........
