12.)Fie a si b -nr.=> a/b=3/2 => a/3=b/2=k => a=3k si b=2k.Inlocuim in: a-b=80 <=> 3k-2k=80 => k=80.Atunci: a=3k=3•80=240 si b=2k=2•80=160._________________________________________10.)Fie x-drumul. x=Izi+IIzi+IIIzi+IVzi <=> x=x/4+x/3+2x/5+20km <=> x-x/4-x/3-2x/5=20km <=> x•(1-1/4-1/3-2/5)=20km <=> x•(60/60-15/60-20/60-24/60)=20km <=> x•(60/60-59/60)=20km <=> x•1/60=20km => x=20•60=120km