Find the area of a rectangle whose length is 6 inches less than 5 times the width and whose perimeter is 8 inches more than twice the length

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.