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 = 5/62/15y + 3/4 -5/6=0(2*4+3*15y-5*10y)/60=08+45y-50y=0-5y=-8y=8/5y=152)5/8m - 7/12m + 5/6m = 1/4 (5*3-7*2+5*4)m=1/4(15-14+20)m=1/421m=1/4m=1/4:21m=1/813)2 1/5 - 3/4m = 59/6011/5 - 3/4m = 59/60- 3/4m = 59/60-5/83/4m=(59*2-5*15)/1203/4m=(118-75)1203/4m=43/120m=43/120:3/4m=43/120*4/3m=43/90