Question 997028
n = number of nickels
d = number of dimes
q = number of quarters


5n + 10d + 25q = 470
q = d + 7
n = 2q


Write everything in terms of d.


5(2(d+7)) + 10d + 25(d + 7) = 470
10d + 70 + 10d + 25d + 175 = 470
45d = 225
d = 5


There are 24 nickels, 5 dimes, and 12 quarters.