Answer:
A. -4-3x>7
Step-by-step explanation:
-4-3(-5)>7
-4-(-15)>7
11>7
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:
d
Step-by-step explanation:
Considering balloon to be an spherical object
Volume of sphere = 
, where r is the radius of sphere.
After 19 minutes ,If radius of balloon changes from r to R, the Volume changes from V to V'.
V'= 
,
As given,rate at which the air leaked out of the balloon (in liters of air per minute) was half of the rate at which Vavilen inflated the balloon.
Also, 
Now, again the radius changes from R to r.So, Volume changes from V' to Back to V.
Time taken by the balloon to deflate = 38 minutes
But there is no relation between time and volume of Balloon.
So, we can't predict at which rate balloon is deflating or inflating.Apart from the statement given in Question:
