Raul has 56 bouncy balls. he puts three times as many balls into red bags as he puts into green gift bags. if he puts the same number of balls into each bag, how many balls does he put into green bags?

If we divide 56 by 4 we get 14.  Why by4?  So that one number is 3 times the other So he had 14 balls that went into the green bags and 42 (56-14) that went into the red bags.  We could just answer the question and say 14 but I think they want to know how many in each green bag.
14 and 42 don't work because they are not the same number of balls.  What number is a common factor?  7 is,
We could have 2 green bags and split the 14 balls into 2 groups of 7 and with the remaining 42 - put them into 6 red bags of 7 each.
And so the answer to your question is:
7 ball in each bag  = 2 bags are green, and 6 bags are red
                                        14 balls              +    42 balls            = 56 bouncy balls