Explanation:
a. The rate of change for the draining water is given by the slope of the line in the graph. We can see that for every minute 40 gallons of water are drained.
Also the slope of this line is negative, so it's -40
b. The initial amount is when the time is zero. It is the y-intercept of the line. In the graph we can see that the line intersects the y-axis at 280. This means that the initial amount was 280 gallons
Answers:
a. -40 (option D)
b. 280 gallons
