The option is the 3rd bubble
<span>30 hours
For this problem, going to assume that the actual flow rate for both pipes is constant for the entire duration of either filling or emptying the pool. The pipe to fill the pool I'll consider to have a value of 1/12 while the drain that empties the pool will have a value of 1/20. With those values, the equation that expresses how many hour it will take to fill the pool while the drain is open becomes:
X(1/12 - 1/20) = 1
Now solve for X
X(5/60 - 3/60) = 1
X(2/60) = 1
X(1/30) = 1
X/30 = 1
X = 30
To check the answer, let's see how much water would have been added over 30 hours.
30/12 = 2.5
So 2 and a half pools worth of water would have been added. Now how much would be removed?
30/20 = 1.5
And 1 and half pools worth would have been removed. So the amount left in the pool is
2.5 - 1.5 = 1
And that's exactly the amount needed.</span>
$100x should be greater than or equal to $2500. X being the number of computers sold. If you divide 100 by 2500 you will know how many computers he need to sell.
$100x >(or equal to) $2500
<u>Part A</u>
<u />
So, the x-intercepts are 
<u>Part B</u>
The vertex will be a minimum because the coefficient of 
is positive.
The x-coordinate of the vertex is 
Substituting this back into the function, we get 
So, the coordinates of the vertex are 
<u>Part C</u>
Plot the vertex and the x-intercepts and draw a parabola that passes through these three points.
The graph is shown in the attached image.
