4•30-5•15=120-75=45
1. 3,6/m = 2,8/4,2
2,8*m = 3,6*4,2
m = 3,6*4,2/2,8
m = 5,4
2. 104/65 = 72/y. 104*y =65*72. y= 65*72/104. y=45