Your answer is D)16. To find the average, add up all the numbers and divivde by the number of numbers there is
So here’s a example and formula
Vertex form uses the following formula:

Identify the values of h and k in your function:


The vertex is found with the following point:


The vertex will be found at
(-5, -28).
1. Pick two points on the line and determine their coordinates.
2. Determine the difference in y-coordinates of these two points (rise).
3. Determine the difference in x-coordinates for these two points (run).
4. Divide the difference in y-coordinates by the difference in x-coordinates (rise/run or slope).