Explanation:
The slope is described by the the initial and final value of one quantity over the difference between the initial and final of the other
Rate: for points on a Cartesian plane,(x1, y1) and (x2, y2)
the slope, m= (y2 - y1)/(x2 - x1)
The rate of change on the other hand is mostly refers to how much a quantity is changing with time i.e the rate of change of y from y1 to y2 can be expressed as
rate = (y2 - y1)/(t2 - t1)...where t1 and t2 are the various time in y1 and y2 respectively...