Answer:
a. Dan is 100 miles from home at noon and is travelling at 70 miles per hour.
Explanation:
Given

Required
Interpret
An equation has the form

Where


By comparison with


i.e. He travels at 70 miles per hour
And

This represents the initial distance as at when he started travelling (12 noon)
i.e. At noon, he is 100 miles away from home