Answer:
[Vertex form]
Step-by-step explanation:
Given function:

We need to find the vertex form which is.,

where
represents the co-ordinates of vertex.
We apply completing square method to do so.
We have

First of all we make sure that the leading co-efficient is =1.
In order to make the leading co-efficient is =1, we multiply each term with -3.


Isolating
and
terms on one side.
Subtracting both sides by 15.


In order to make the right side a perfect square trinomial, we will take half of the co-efficient of
term, square it and add it both sides side.
square of half of the co-efficient of
term = 
Adding 36 to both sides.


Since
is a perfect square of
, so, we can write as:

Subtracting 21 to both sides:


Dividing both sides by -3.

[Vertex form]
Answer:
When we have something like:
![\sqrt[n]{x}](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%7Bx%7D)
It is called the n-th root of x.
Where x is called the radicand, and n is called the index.
Then the term:
![\sqrt[4]{16}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B16%7D)
is called the fourth root of 16.
And in this case, we can see that the index is 4, and the radicand is 16.
At the end, we have the question: what is the 4th root of 16?
this is:
![\sqrt[4]{16} = \sqrt[4]{4*4} = \sqrt[4]{2*2*2*2} = 2](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B16%7D%20%3D%20%5Csqrt%5B4%5D%7B4%2A4%7D%20%20%3D%20%5Csqrt%5B4%5D%7B2%2A2%2A2%2A2%7D%20%3D%202)
The 4th root of 16 is equal to 2.
Answer:
Step-by-step explanation:
hello:
x²-4x=0 means : x(x-4)=0
x=0 or x-4=0
conclusion : x=0 and x= 4 ...answer : B
Answer:
1.5 for each song.
Step-by-step explanation:
subtract $6.99 by $21.99 = 15 divided by 10 = 1.5