Answer:
17
Step-by-step explanation:
f(x) = x + 8
f(9) = 9 + 8
= 17
Answer: 9 students
Step-by-step explanation:
15+8+3=26
35-26= 9
The vertex is 
Explanation:
The equation is 
To find the vertex, we need the equation in the form of 
Dividing each term by 2 in the equation 

Now, completing the square by adding and subtracting 1, we get,

The first three terms can be written as
,
![f(x)=2[(x+1)^{2}+\frac{1}{2} ]](https://tex.z-dn.net/?f=f%28x%29%3D2%5B%28x%2B1%29%5E%7B2%7D%2B%5Cfrac%7B1%7D%7B2%7D%20%20%5D)
Multiplying 2 into the bracket, we get,

This equation is of the form 
Now, we shall find the vertex 
Thus,
and 
Thus, the vertex is 
I don’t know if this is right but the way I did it I got 7.5
9/2
9 x 2 and 2 x 2 is equal to 18/4
9 x 3 and 2 x 3 is equal to 27/6
9 x 4 and 2 x 4 is equal to 36/8
I did the best I could to understand this problem. Do not quote me on this please.