Answer:
b~ 32
Step-by-step explanation:
Answer:
90 engines must be made to minimize the unit cost.
Step-by-step explanation:
Vertex of a quadratic function:
Suppose we have a quadratic function in the following format:

It's vertex is the point 
In which


Where

If a>0, the minimum value of the function will happen for 
C(x)=x²-180x+20,482
This means that 
How many engines must be made to minimize the unit cost?
x value of the vertex. So

90 engines must be made to minimize the unit cost.
Answer:
B. 0.54
Step-by-step explanation:
Answer:
A.b = 210 + 15x
B.b = 210 – 15x
C.b = 195 + 15x
D.b = 195 – 15x
Step-by-step explanation
B is correct. Your starting amount is 210$ And you're taking away 15$ each time she uses the club,x.
Sally can paint a house in 4 hours; Which means in 1 hour she can paint 1/4th of the house.
John can paint the same house in 6 hours. Which means in 1 hour she can paint 1/6th of the house.
Together in 1 hour they can paint: - 1/4 + 1/6 = 5/12th of the house.
Total Hours for painting the house together will be 12/5 = 2.4 Hours.
So the answer is 2 hours and 24 minutes
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