Answer:
solve for y is y
=
x
+
3
Solve for x is x
=
−
3
+
y
Step-by-step explanation:
Vertex form is

where (h,k) is the vertex.
We can see that the vertex of the graph is at (2,0), and that the graph opens downwards, but does not look stretched at all.
Therefore,
a = -1
h = 2
k = 0
and our vertex form equation is

which is answer A
Check the picture below, that's just an example of a parabola opening upwards.
so the cost equation C(b), which is a quadratic with a positive leading term's coefficient, has the graph of a parabola like the one in the picture, so the cost goes down and down and down, reaches the vertex or namely the minimum, and then goes back up.
bearing in mind that the quantity will be on the x-axis and the cost amount is over the y-axis, what are the coordinates of the vertex of this parabola? namely, at what cost for how many bats?

![\bf \left( -\cfrac{-7.2}{2(0.06)}~~,~~390-\cfrac{(-7.2)^2}{4(0.06)} \right)\implies (60~~,~~390-216) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill (\stackrel{\textit{number of bats}}{60}~~,~~\stackrel{\textit{total cost}}{174})~\hfill](https://tex.z-dn.net/?f=%5Cbf%20%5Cleft%28%20-%5Ccfrac%7B-7.2%7D%7B2%280.06%29%7D~~%2C~~390-%5Ccfrac%7B%28-7.2%29%5E2%7D%7B4%280.06%29%7D%20%5Cright%29%5Cimplies%20%2860~~%2C~~390-216%29%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20~%5Chfill%20%28%5Cstackrel%7B%5Ctextit%7Bnumber%20of%20bats%7D%7D%7B60%7D~~%2C~~%5Cstackrel%7B%5Ctextit%7Btotal%20cost%7D%7D%7B174%7D%29~%5Chfill)
I don't understand your question.. Is this multiple choice or something else?
Answer: 104.5 seconds
Step-by-step explanation:
Hi, to answer this question we have to apply proportions:
Six students eat 6 apples in 33 seconds.
The proportion is: number of apples eaten /time
6 apples /33 seconds = 6/33
For 19 apples:
19 apples / x seconds =19/x
6/33 = 19/x
Solving for x:
x = 19 / ( 6/33)
x = 104.5 seconds
Feel free to ask for more if needed or if you did not understand something.