15х+10=7+12у
15х+3=12у
5х+1=4у
у=(5х+1)/4 х= (4у-1)/5
4х+4у+х=31
5х+4у=31
у=(31-5х)/4 х=(31-4у)/5
124/3=41 целая b дробь 1/3= 41 1/3