Question

Lisa wrote a business plan for an entrepreneurship class, and now she has to make bound copies. Lisa could use a printer who charges a setup fee of $40 and $5 for every copy printed. Another possibility is to go to the office supply store, where she could pay an up-front fee of $30 and $10 per copy. There is a certain number of copies that makes the two options equivalent in terms of cost. How many copies is that?Write a system of equations, graph them, and type the solution.

Answer 1

The equation for the first option would be

$y=40+5x$

Where "x" is the number of copies and y the cost.

The second equation will be

$y=30+10x$

If we graph both equations we have

As we can see, they will be equal in terms of cost with 2 copies. The cost will be 50.

We can see it at the intersection of the two graphs! we can also do it with algebra, if the costs are equal (same "y") we can say

$\begin{gathered} 40+5x=30+10x \\ \\ 10=5x \\ \\ x=2 \end{gathered}$

The number of copies is 2.