I have to solve a coin word problem using a method called HES (Heading, Equation, Solution). In the problem, there are 3 unknowns and we have to have 2 equations so that we can either use substitution or elimination.
I have to let x=?(something)
2x=?(something)
y=? (something)
The word problems is as follows:
Jamie has $3 in nickels, dimes, and quarters. If she has twice as many dimes as quarters and five more nickels than dimes, how many coins of each type does she have?

Same thing here. Can you try to say which can be x and which can be y?