a Let f(x) be the distance traveled in x hours. How would you find the distance traveled in this case?
B
b Begin by changing years into hours.
A
a f(x)=9x
B
b 157 680 miles
Practice makes perfect
a Let f( x) be the distance traveled in x hours. In this case the distance traveled can be found by multiplying the rate of 9 mph by the number of hours.
f( x)= 9 x
b To find the distance traveled in 2 years, we should first change years into hours. Since this will involve multiple conversion factors, let's organize them in a table.
Starting Unit
Converted Unit
1 year
365days
1day
24 hours
To perform this conversion, we need to multiply the given value by all of these conversion factors. Remember, we need to arrange these ratios such that every unit we do not want gets canceled out and only the units that we want will remain.
This means that 2 years is the same as 17 520 hours. Therefore, we can find the distance traveled by substituting 17 520 for x in the function from Part A.
