cu .... mai mari - aplici adunarea
2/6 + 1/4 = 1/3 + 1/4 amplifici 1/3 cu 4, 1/4 cu 3
4/12 + 3/12 = 7/12
2/6 + 4/6 = 8/6 = 4/3
2/6+2/6 = 4/6 = 2/3
2/6+3/6 = 5/6
