Geometry the area of a rectangle is x 3 + 8x 2 + 13x – 12 square units. the width of the rectangle is x + 4 units. what is the length of the rectangle?

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.