algebra
posted by Maura on .
O.k. I'm 42 trying to help my nephew with algebra and lets just say it's been awhile....
Total money $ 101.25
45 more dimes than nickels
3 times as many quarters as dimes.
How many nickels, dimes & quarters?

d times
n nickels
q quarters
d = (n + 45)
q = 3 d so q = 3(n+45)
5 n + 10 d + 25 q = 10125
n + 2 d + 5 q = 2025
so
n + 2 (n+45) + 15 (n+45) = 2025
n + 17(n+45) = 2025
18 n + 765 = 2025
18 n  1260
n = 70 nickels
you can get the rest now 
Got it. Man that felt good to actually solve a problem after all these years.

Hey, at least you are not 74 and trying to help :)