Answer:
The vertex of the function
is 
Step-by-step explanation:
I've graphed this on desmos for a visual
Option C: x = 5.5 is the value of x
Explanation:
Given that CD, AE, an BF are the medians of the triangle ABC
Also, given that
and 
We need to determine the value of x.
Since, we know that the centroid divides the median in the ratio 2 : 1
Hence, we have,

Substituting the values, we get,

Simplifying, we get,

Subtracting both sides of the equation by 2x, we have,

Adding both sides of the equation by 5, we have,

Dividing both sides of the equation by 2, we get,

Therefore, the value of x is 5.5
Hence, Option C is the correct answer.
Answer:
The sum of the areas of all the surfaces (faces) of a three-dimensional figure.
Step-by-step explanation:
It should be all real numbers