6/60-х=13/60-9/60
6/60-х=4/60
х=6/60+4/60
х=10/60
13/60+6/60-10/60=9/60
8/100+х=20/100-5/100
8/100+х=15/100
х=15/100-8/100
х=7/100
5/100+8/100+7/100=20/100
6/60-х=13/60-9/60
6/60-х=4/60
х=6/60+4/60
х=10/60
13/60+6/60-10/60=9/60
8/100+х=20/100-5/100
8/100+х=15/100
х=15/100-8/100
х=7/100
5/100+8/100+7/100=20/100