Răspuns :
3/5*1/3-1/4*m = 15/100
1/5-m/4 = 3/20
4/20 - 5m/20 = 3/20
(4-5m)/20 = 3/20
4-5m = 3
5m = 1
m = 1/5
1/5-m/4 = 3/20
4/20 - 5m/20 = 3/20
(4-5m)/20 = 3/20
4-5m = 3
5m = 1
m = 1/5