please help. I don't understand this. 50PTS

Function A(e) represents the surface area of a cube in terms of its edge length, e, and the difference quotient is 12e + 6h. What is the average rate of change in surface area of a cube as the edge length increases from 3 inches to 5 inches?

48 square inches per inch
54 square inches per inch
66 square inches per inch
96 square inches per inch

please help I dont understand this 50PTS Function Ae represents the surface area of a cube in terms of its edge length e and the difference quotient is 12e 6h W class=