Answer:
14 dvd cases
5 envelopes
Explanation:
We need to find the least common multiple of 5 and 14
Find the prime factors
5 = 5*1
14 = 2*7
Multiple them together
2*5*7 = 70
The least common multiple is 70
70/5 = 14 so we need to buy 14 dvd cases
70/14 = 5 so we need to buy 5 envelopes