Craig bought a treadmill for 400 dollars He estimates that the annual costs to maintain the machine will be 36 dollars Which rational function yields the average annual cost in dollars of owning the treadmill for x years?

Over x years, the treadmill costs $400 to buy and $36 each year to maintain, so the total cost is 400 + 36x dollars. The average annual cost is total cost divided by x years: f(x) = (400 + 36x)/x. This matches choice B.

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