cmmdc este 5
rezulta a=5m si b=5n ,
a/(1/4)=b/(1/3)
4a=3b : 4b
a/b=3/4
(5m)/(5n)=3/4
m=3 si n=4
a=5*3=15
b=5*4=20
2.cmmdc este 30
rezulta a=30m si b=30n ,
3a=5b :3b
a/b=5/3
(30m)/(30n)=5/3
m=5 si n=3
a=30*5=150
b=30*3=90
3.cmmmc este 120
rezulta a=120/m si b=120/n ,
3a=5b :3b
a/b=5/3
(120/m)/(120/n)=5/3
n/m=5/3
m=3 si n=5
a=120/3=40
b=120/5=24