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]
A because it’s the right answer
60×120=7200
7200÷100=72
60+72=132
answer=£132
hope this helps.....
Answer:
x=12/5
Step-by-step explanation:
x*5/12=1
x=1*12/5
x=12/5
Answer:
And then the percentage between 24 and 40 would be 
Step-by-step explanation:
For this problem we have the following parameters given:
And for this case we want to find the percentage of lightbulb replacement requests numbering between 24 and 40.
From the empirical rule we know that we have 68% of the values within one deviation from the mean, 95% of the values within 2 deviations and 99.7% within 3 deviations.
We can find the number of deviations from themean for the limits with the z score formula we got:
And replacing we got:
And then the percentage between 24 and 40 would be
