A local computer center charges nonmembers $5 per
session to use the media center. If you pay a membership fee of $25, you pay
only $3 per session. Write an equation that can help you decide whether to
become a member. Then solve the equation and interpret the solution.
Let N = the number of sessions you will need.
If you don't become a member then your total cost for
the N sessions will be $5N
If you do become a member then your total cost for the
N sessions will be $25 + $3N
Now we set those equal to each other to find the value
of N when they will cost the same.
5N = 25 + 3N
That's the equation. We solve it
2N = 25
N = 12.5
That's halfway between two integers, 12 and 13.
Interpretation. If you will need 12 or fewer sessions, then
you should not become a member. But if you will need 13 or
more sessions, then you should become a member.
Edwin