The function is graphed as shown below
Part A:
We use the formula

to find the vertex of the function. A quadratic function of the form of

and equating this form to the given function

, we have

and

.
Substituting

and

into the vertex formula, we have

, as shown in the graph
This calculation means that the highest profit is achieved when the number of photo printed equals to ten photos
Part B:
We can find solution to this equation by factorising





and

, as shown in the graph
The two values means that the company makes no profit when they either produce 5 or 15 photos
Answer:

Step-by-step explanation:
The midpoint of any line segment is the average of the x- and y-values of the two endpoints.
Therefore, the midpoint of
is
.
So, the answer is
and we're done!
Answer:
129
Step-by-step explanation:
Considering the survey to be representative, you can simply multiply the share of students <em>p</em> preferring “Track & Field” with the whole school population at the same time to estimate the number of such students in the whole school.
First we need to find the relative share <em>p</em> of such answers in the study by dividing it by the sum of answers, assuming that the table is complete for that random sample:
<em>p</em> = 4/(8 + 5 + 4) = 4/17
Then for the whole school we get 550 <em>p</em> ≈ 129.4
It is positive.
Hope this helped.