Answer:
a) f(n) = 12n +8
b) f(10) = 128
c) The problem statement tells you this is the distance, in miles, from the store after Mila has traveled after 10 hours.
Explanation:
a) The common difference of this arithmetic sequence is the difference between the 2nd and 1st terms: 32 - 20 = 12.
The initial value of the sequence is the value when n=1, namely 20.
Then the explicit formula for the sequence can be written:
... f(n) = 20 + 12(n -1)
and simplified to
... f(n) = 12n +8
b) To find f(10), we put 10 where n is in the formula and do the arithmetic:
... f(10) = 12·10 +8 = 120 +8 = 128
c) For the interpretation, we look to the definition of the function provided in the problem statement.