Answer:
So, d(4)=68. That means that after 4 hours, Joanna has cycled 68 miles.
Explanation:
First, we need to find what d(4) equals. In this equation t=4, so to solve plugin 4 and simplify. Therefore, the equation is
. Once you multiply and add you get d(4)=68; this answers the first question.
Then, the next two questions ask you to interpret this answer. To do that go back and read what each variable stands for. "t" is for the time Joanna has cycled. So, in the equation d(4), 4 hours have passed. Additionally, "d(4)" represents the number of miles she has ridden. This means since d(4)=68 she has cycled 68 miles.
Note that since I cannot see the options I guessed at the exact wording, but the answers should be similar to what I wrote.