Let's first create an equation. We'll set out total, <em>t</em>, equal to our initial value times d, or days, for each additional day.
That means that we have 1.39 as our initial, upfront value. It's not affected by anything else, and is a one-time payment. For each additional day, we have to pay 50 cents, so to find our how much in a given day, we use:
t = 1.39 + .50d
We multiply the .50 times each day because every day, we pay 50 cents for each additional day.
Now, we can plug in 6 for d. We plug in 6 because we've already accounted for one day with that one-time initial value. We have:
