2/15y + 3/4 = 5/6 5/8m - 7/12m + 5/6m = 1/4 2 1/5 - 3/4m = 59/60

2/15y + 3/4 = 5/6 2/15y + 3/4 -5/6=0 (2*4+3*15y-5*10y)/60=0 8+45y-50y=0 -5y=-8 y=8/5 y=15 2) 5/8m - 7/12m + 5/6m = 1/4  (5*3-7*2+5*4)m=1/4 (15-14+20)m=1/4 21m=1/4 m=1/4:21 m=1/81 3)2 1/5 - 3/4m = 59/60 11/5 - 3/4m = 59/60 - 3/4m = 59/60-5/8 3/4m=(59*2-5*15)/120 3/4m=(118-75)120 3/4m=43/120 m=43/120:3/4 m=43/120*4/3 m=43/90