The rate of change in a linear equation of the form:
is m. This means that for carpet company A the rate of change is 1.35 and for company B the rate of change is 2.05.
Therefore, company B has the greatest rate of change.
The rate of change is the same as the slope in a line. This means that the greater the rate of change is the faster the line will grow. This can be seen in the following graph:
where the red line is the graph for company A and the blue line is the graph for company B.