Answer:
The given expression is
[tex]15+c=17.50[/tex]
We can use this expression to model the cost for a service.
Let's say that your gardener charges an initial amount of $15, and an additional per hour. If the gardener worked only for one hour, and the total cost charged was $17.50, how much was the additional cost?
So, the given expression models this real life situation, we can answer the problem by just solving the equation for [tex]c[/tex]
[tex]15+c=17.50\\c=17.50-15\\c=2.50[/tex]