Question 1017656
n = number of 5 cent coins
q = number of 25 cent coins


n = q + 12
5n + 25q = 900


Plug in the first equation into the second.


5(q + 12) + 25q = 900
5q + 60 + 25q = 900
30q = 840
q = 28


Jon has 28 25-cent coins and 40 5-cent coins.