<h3>
Answer: 15x^(7/3) - 8x^(7/4) + x + 9000</h3>
=========================================================
Explanation:
If you know the cost function C(x), to find the marginal cost, we apply the derivative.
Marginal cost = derivative of cost function
Marginal cost = C ' (x)
Since we're given the marginal cost, we'll apply the antiderivative (aka integral) to figure out what C(x) is. This reverses the process described above.


D represents a fixed constant. I would have used C as the constant of integration, but it's already taken by the cost function C(x).
To determine the value of D, we plug in x = 0 and C(x) = 9000. This is because we're told the fixed costs are $9000. This means that when x = 0 units are made, you still have $9000 in costs to pay. This is the initial value. You'll find that all of this leads to D = 9000 because everything else zeros out.
Therefore, we go from this

to this

which is the final answer.
I can add u to a snap gc where we help each other with work
Answer:
5/3 or 1.67
Step-by-step explanation:
Find the slope of the original line
3x+5y=4 Subtract 3x from both sides
5y = - 3x + 4 Divide both sides by 5
y = (-3/5)x + 4
The original line has a slope of - 3/5 or - 0.6
Find the slope of the perpendicular line
m1 * m2 = - 1
m1 = - 3/5
m2 = -1/(-3/5)
m2 = 5/3
The slope of the perpendicular line is
5/3 or 1.67
The speed of the airplane is the ratio of the distance to the time
The initial average speed of the airplane is approximately 110.8 mph
Reason:
Given parameters are;
The distance between Portland Oregon and Seattle Washington = 145 miles
The decrease in travel time when the speed is increase by 20 mph = minutes
The initial speed of the airplane, v = Required;
Solution;


Therefore;

Which gives;

Therefore
0.2·v² + 4·v - 2,900 = 0
v ≈ ±110.8 mph
The initial average speed of the airplane, v≈ ± 110.8 mph
Learn more here:
brainly.com/question/11365874
ANSWER X=4. You basically plug what y equals to into the second equation the solve for x.