Answer:
(-3,-6) and (-3,2)
Step-by-step explanation:
A line with an undefined slope is vertical. In this case it must have x coordinates equal to -3
Here is our profit as a function of # of posters
p(x) =-10x² + 200x - 250
Here is our price per poster, as a function of the # of posters:
pr(x) = 20 - x
Since we want to find the optimum price and # of posters, let's plug our price function into our profit function, to find the optimum x, and then use that to find the optimum price:
p(x) = -10 (20-x)² + 200 (20 - x) - 250
p(x) = -10 (400 -40x + x²) + 4000 - 200x - 250
Take a look at our profit function. It is a normal trinomial square, with a negative sign on the squared term. This means the curve is a downward facing parabola, so our profit maximum will be the top of the curve.
By taking the derivative, we can find where p'(x) = 0 (where the slope of p(x) equals 0), to see where the top of profit function is.
p(x) = -4000 +400x -10x² + 4000 -200x -250
p'(x) = 400 - 20x -200
0 = 200 - 20x
20x = 200
x = 10
p'(x) = 0 at x=10. This is the peak of our profit function. To find the price per poster, plug x=10 into our price function:
price = 20 - x
price = 10
Now plug x=10 into our original profit function in order to find our maximum profit:
<span>p(x)= -10x^2 +200x -250
p(x) = -10 (10)</span>² +200 (10) - 250
<span>p(x) = -1000 + 2000 - 250
p(x) = 750
Correct answer is C)</span>
Answer:
The area of the figure is 28 units².
Step-by-step explanation:
Find the area of the full rectangle, ignoring the triangle.
Then, find the area of the triangle:
Finally, subtract:
Answer:
16 men would be needed to paint the room in 2 hours
Step-by-step explanation:
We can use proportion to solve the problem given, but first we need to determine whether it is a direct or indirect proportion.
If the number of men are increase, the time taken to do the work will decrease, If the number of men are decrease, the time taken to do the work will increase. Therefore, this is an indirect proportion.
We are going to arrange the data inversely.
Let x be the number of men needed to paint the room in two hours
8 hours = 2 hours
x = 4 men
Cross-multiply
2×x = 8×4
2x = 32
Divide both-side of the equation by 2
2x/2 = 32/2
x = 16 men
16 men would be needed to paint the room in 2 hours
As a formula, you're saying 4*(n-7)=32
This solves to n-7 = 8, so n=15
