Answer:
D. Up
Step-by-step explanation:
When a parabola has the form
, It is vertical (opens up or down).
Because the variable "x" is squared.
If "a" is positive, then the parabola opens up, but if it is negative, then the parabola opens down.
In this case you have the quadratic function:

Which can be rewritten as:
Therefore, it is vertical, because it has the form: 
You can observe that the value of "a" is:

Then, since "a" is positive, the parabola opens up.
Answer:
All of the options when substituted for b will make the root of b irrational
Step-by-step explanation:
Mathematically, surds are roots of non-perfect squares and they are tagged as irrational numbers
For b to be irrational, all of the numbers given would fit. This is because all of these numbers are non-perfect squares meaning they do not have square root.
So what this mean is that these numbers when put under the root umbrella are irrational numbers as they are not perfect squares
Answer:
The value of f is 80.6.
Step-by-step explanation:
We are given the equation and asked to solve for f.
If we are given a fraction with a variable in the numerator, we can multiply both sides of the equation by the denominator to isolate it.
For example, if you look at this equation:

We can multiply both sides by 26 to get the a by itself so the equation can be solved.

Therefore, we can apply this same technique to the equation 

Therefore, the value of f is 80.6.
Answer:
C≈25.13ft
Step-by-step explanation:
Using the formulas
C=2πr
d=2r
Solving for C
C=πd=π·8≈25.13274ft
There aren't really any instructions for this, so I'll just go ahead and find the total amount of money for both months. The first month Adriano had 200 subscribers. 5 times 200 is 1000, so Adriano received $1000 that month. The second month 40 members joined, but 10 cancelled their subscription. Taking this into account, we'll just say that 30 members joined. 30 times 5 is 150, and 150 plus 1000 is 1150. Therefore, Adriano had to have received $1150 the second month.
I'm not entirely sure what the question was to begin with, but I hope this answers it!