Answer:
The answer is below
Explanation:
The equation of a graph of a linear function is in the form:
y = mx + b;
where m is the slope of the graph, b is the y intercept, y and x are the variable.
Since y represent distance on y axis and t represent time on the x axis. We see that the graph passes the points:
(0, 100) and (6, 400). The equation of the graph is:

a) The y intercept is 0. This means that initially the car is at 100 miles from Phoenix before the trip started. i.e. at 0 hours the distance is 100 miles.
b) The slope of the graph is 50. It means that the car traveled at a speed of 50 miles per hour
c) The end point of the graph is (6, 400), meaning the trip lasted 6 hours
d) The end point of the graph is (6, 400), meaning at the end of the trip, the car was 400 miles from Phoenix.