Answer:

Step-by-step explanation:
The standard form of a quadratic equation is 
The vertex form of a quadratic equation is 
The vertex of a quadratic is (h,k) which is the maximum or minimum of a quadratic equation. To find the vertex of a quadratic, you can either graph the function and find the vertex, or you can find it algebraically.
To find the h-value of the vertex, you use the following equation:

In this case, our quadratic equation is
. Our a-value is 1, our b-value is -6, and our c-value is -16. We will only be using the a and b values. To find the h-value, we will plug in these values into the equation shown below.
⇒ 
Now, that we found our h-value, we need to find our k-value. To find the k-value, you plug in the h-value we found into the given quadratic equation which in this case is 
⇒
⇒
⇒ 
This y-value that we just found is our k-value.
Next, we are going to set up our equation in vertex form. As a reminder, vertex form is: 
a: 1
h: 3
k: -25

Hope this helps!
Answer:
Step-by-step explanation:
Since there's no one one number you can add to one number in the sequence to get to the next number, this is not arithmetic. It must be geometric. We need then to find the common ratio. Let's start with the first 2 numbers, find a ratio, and then use it to test for accuracy.
10x = 15 and
x =
If this is in fact a geometric sequence witha common ratio of 3/2, we should be able to multiply 15 by 3/2 to get to the next number in the sequence. Let's try it out:
Good. So the common ratio is 3/2. The formula for an explicit geometric formula is
where a1 is the first number in the sequence and r is the common ratio. Filling in:

Since
are in arithmetic progression,




and since
are in geometric progression,




Recall that


It follows that

so the left side is

Also recall that

so that the right side is

Solve for
.

Now, the numerator increases more slowly than the denominator, since


and for
,

This means we only need to check if the claim is true for any
.
doesn't work, since that makes
.
If
, then

If
, then

If
, then

There is only one value for which the claim is true,
.
Answer:
x=10
Step-by-step explanation:
hope this helps