i'm pretty sure u have to make the denominators the same by finding the LCM (least common multiple). so 3/5 would be 9/15 cuz u have to change the numerator by the denominator. so five times three, three times three. so 9/15 and do the same for the other one. 1/3 equals 5/15. sorry i'm not a teacher but i hope i helped. oh and remember to rebel against favoritism in schools and at home.