4601

數學, 不懂...

Easton Utilities uses the rates shown in the table below to compute the monthly cost of natural gas for each customer.Charges per Month$0.7866 per CCF for the first 5 CCF$0.4601 per CCF for the next 35 CCF$0.2508 per CCF for all over 40 CCFa. Write a compound function for the cost of consuming x CCF (cubic hundred feet) of natural gas and graph the function.b. What would be the cost of consuming 25 CCF of natural gas in a given month?c. What would be the cost of consuming 45 CCF of natural gas in a given month?
Easton Utilities uses the rates shown in the table below to compute the monthly cost of natural gas for each customer.Easton天然氣公司對每個用戶採用下列的費率計算每個月的瓦斯費。

Charges per Month 每月瓦斯費$0.7866 per CCF for the first 5 CCF 前5個CCF

每CCF收$0.7866$0.4601 per CCF for the next 35 CCF 接下來的35個CCF

每CCF收$0.4601$0.2508 per CCF for all over 40 CCF 超過40個CCF以後

每CCF收$0.2508a. Write a compound function for the cost of consuming x CCF (cubic hundred feet) of natural gas and graph the function.寫出並畫出使用xCCF的瓦斯所需的費用函數。

b. What would be the cost of consuming 25 CCF of natural gas in a given month?在一個月中使用25CCF的瓦斯所需費用為何？c. What would be the cost of consuming 45 CCF of natural gas in a given month?在一個月中使用45CCF的瓦斯所需費用為何？[解]a. f(x) = 0.7866x

when x小於等於5f(x) = 0.7786*5 0.4601(x - 5)

when 5