What is the equation for the following. Algebra translation.

Question

How many copies can be made if there is a $2 charge to use the copy machine and copies are 5 cents a piece?

 

At the mall soda costs $1.50 and refills are 75 cents. How much does it cost to buy a soda and have refills?

Answer 1

First question:

 

How much money do you have available?  Suppose it is $M, and the maximum number of copies you can make is n.  Then

 

$2 + $0.05n ≤ $M

 

n ≤ ($M - $2) / ($0.05), with n being an integer

 

Without more information in the problem statement, this is as far as we can go.

 

Second question:

 

Suppose you want n refills.  Let $C = cost.

 

$C = $1.50 + $0.75n

 

Again, without additional information, this is as far as we can go.