Răspuns:
3/7 = a/21
amplificam fractia 3/7 cu 3 si obtinem 9/21=a/21 => a=9
(b+1)/3=4/6
simplificam fractia 4/6 cu 2 si obtinem 2/3=(b+1)/3 => b+1 = 2 => b = 2-1 => b = 1
sper ca te-am ajutat :)))
