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 
Answer:
2/3
Step-by-step explanation:
2/3 is 66 2/3%
Answer:
D. An input (x) can only be with one output (y).
Step-by-step explanation:
5x=15
X=3
2(3)+y=5
Y= -1
(3,-1)