Answer:
Step-by-step explanation: first write it as an equation f(x)=15(x) +45 and then plug in 3 because you are finding for 3 hours. It would look like this f(3)=15(3) + 45. Then you solve it, 15 times 3 equals 45. f(3) =45+45 and then add f(3)=45+45. And the answer is f(3)=90. HOPE THAT HELPS.
