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: n+2
Two lawns more than last week so two more than something with n being that something is; n+2
Answer:
3x−4y=9 −3x+2y=9
Add these equations to eliminate x: −2y=18
Then solve−2y=18
for y: −2y=18 −2y −2 = 18 −2 (Divide both sides by -2)
y=−9
Now that we've found y let's plug it back in to solve for x.
Write down an original equation: 3x−4y=9
Substitute−9for y in 3x−4y=9: 3x−(4)(−9)=9
3x+36=9(Simplify both sides of the equation)
3x+36+−36=9+−36(Add -36 to both sides)
3x=−27 3x 3 = −27 3 (Divide both sides by 3) x=−9
Answer: x=−9 and y=−9
Hope This Helps!!!
frankly yes, because when you want inverse a function you must inverse it with line x=y
so when you inverse a function Df and Rf will convert together!