2х+1=8х+5+20
2х-8х=5+20-1
-6х=24
х=24/-6
х=-4
3х=45-10х
3х+10х=45
13х=45
х=45/13
х=3,46153846154
9-у=2у
-у-2у=-9
-3у=-9
у=3
2х+1=8х+5+20
2х-8х=5+20-1
-6х=24
х=24/-6
х=-4
3х=45-10х
3х+10х=45
13х=45
х=45/13
х=3,46153846154
9-у=2у
-у-2у=-9
-3у=-9
у=3