Question 854180
This is a problem in a very specific form.  The suggestion I will make is that you look at the solution in another answered question which is also of this same form.  


I refer to that question and solution in this link:
<a href="http://www.algebra.com/algebra/homework/coordinate/word/Linear_Equations_And_Systems_Word_Problems.faq.question.854177.html">Another revenue and item count exercise which is this same form, solved but all in symbols.</a>