Răspuns:
a. 5/12+9/12=14/12 Simplificam cu 2= 7/6
b. 4/15-7/15=-3/15 simplificam cu 3=-1/5
a. 5/12 + 9/12 = 5+9/12 = 14/12
b. 7/15 - 4/15 = 7-4/15 = 3/15