[a,(b)+b,(a)]/(a+b)=(a+b)/3a
Calculam a,(b)+b,(a)=(ab-a)/9 +(ba-b)/9=
(10a+b-a+10b+a-b)/9=10(a+b)/9
Ecuatia devine: [10(a+b)/9]/(a+b)=(a+b)/3a
10/9=(a+b)/3a
10/3=(a+b)/a
10a=3(a+b)
10a=3a+3b
7a=3b
7 si 3 sunt prime intre ele, rezulta a=3 si b=7
ab=37
