In my pocket I have dimes and nickels worth $1.55. In total I have 19 coins How many of each coin do I have?
n = nickels value = 5n
d = dimes = 19-n value = 10(19-n)
values summed = 155
5n + 10 (19-n) = 155 solve for n , the number of nickels, then d = 19 - n