A rental car company charges $45 per day for the rental of a midsize car.
Additionally, there is a tax of8% on all car rentals. Which of the following functions
c best represents the total charge, including tax, in dollars, to rent the midsize car
for d days?
A.c(d)=45.08d
B.c(d)=45d+1.08
C.c(d)=45*0.08d
D.c(d)=45*1.08d
重点单词：
function ['fʌŋkʃən] n. 功能，函数，职务，重大聚会
original [ə'ridʒənl] adj. 最初的，原始的，有独创性的，原版的
multiple ['mʌltipl] adj. 许多，多种多样的
答案：D
解析：
Since the daily charge for the car is $45, the tax rate is 8%, and the rental is for d
days, the total rental charges can be represented by the expression45*1.08*d.
Note that adding an 8% tax to the original amount is the same as using 108% of
the original amount, which is achieved by multiplying by 1.08.
Since c(d) represents the total rental charges, including tax, over d days, the
function that best models this is: c(d)=45*1.08d.
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