Question

I have 7 bucks worth of quarters and nickels, how many nickels and quarters do I have in a system of equations thing.

Answer 1

25q + 5n = 700

5q + n = 140
n = 140 - 5q , where 0 < q < 28

e.g. let q = 10, then n = 90

so 10 quarters + 90 nickels = 10(25) + 90(5) = 700

clearly you don't have a unique solution, since you have only
one equation but two variables, but
since n and q must be whole numbers, there is a finite number of
solutions , namely 9 < q < 28