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