Question 687517
Let q be the number of quarters and n be the number of nickels.  The most important thing here is to understand that q is the NUMBER of nickels, not how much they are worth (same with q and quarters).
so, .25q+.05n=4 
now we need to look at the relationship of quarters to nickels.  It is tricky sometimes to write this part, is it 3n=q or 3q=n???  I read this as she has more quarters than nickels, (3 times as many to be exact).  So which one would make the number of quarters larger than the number of nickels?  3n=q
I would use substitution at this point.
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