Thanks for your reply! I apologize for not being thorough. I see from my original post that I screwed up typing the problem. The problem is f(x)=x^{2}-2x from x_{1}=3 to x_{2}=6. Sorry!

1. The instructions to the problem state: Find the average rate of change of the function x_{1} to x_{2}.

So follow the algorithm they gave you: plug the interval endpoints (the x-values) into the formula for f(x), find the corresponding y-values, and find the slope of the line through these two (x, y) points.

I did not know what to do with the x^{2}-2x part.

I'm sorry, but I don't understand what this means. How did you find the values for f(x) if you didn't use the formula, x^2 - 2x, for f(x)?