Răspuns :
Trebuie sa aduci la acelasi numitor:
(1/2-1/5) x 10/3 = (5 - 2) / 10 x 10 / 3 = 3 / 10 x 10 / 3 = 30 / 30 = 1
(1/2-1/5) x 10/3 = (5 - 2) / 10 x 10 / 3 = 3 / 10 x 10 / 3 = 30 / 30 = 1