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.
8500 you make two fractions set equal to eachother.. 6290/x (x is the missing number) and 74/100 (the percentage) you cross multiply the 6290 and 100 which is 629000 and divide it by the 74 which is 8500 which should be your answer
