In calculus, we use derivatives to find the instantaneous rate of change at any point on a graph. To find the average rate of change, we just find the slope of the secant line that intercepts two points on the graph.
We find slope with the following equation:

In this case, we are looking for the slope from x = -1 to x = 1. We have both x values, so next we need the y values.
F(-1) = (-1)^2 - (-1) - 1 = 1
F(1) = (1)^2 - (1) - 1 = -1
Now plug in the x and y values to find the slope:
The answer is -1.
Six and eighty hundred thirty seven thousandths
Okay so we have to first find the total.
8+3+5= 16 candies
7+4+9= 20 drinks
Since she wants to get a yellow candy and any drink but orange, put that information as a fraction.
8/16= 50% or 1/2
11/20= 55% (By the way you get 11 because of the 7 red and 4 blue).
And that's your answer!
Hope this helped and good luck! ^=^