Using the vertex of the quadratic function, it is found that:
a) The maximum number of customers in the store is at 12 P.M.
b) 75 customers are in the store at this time.
The number of customers in x hours after 7 AM is given by:
Which is a quadratic equation with coefficients 
Item a:
The maximum value, considering that a < 0, happens at:
Hence:
5 hours after 7 A.M, hence, the maximum number of customers in the store is at 12 P.M.
Item b:
The value is y(5), hence:
75 customers are in the store at this time.
A similar problem is given at brainly.com/question/24713268
Answer: Level of the liquid dropping at 28.28 inch/second when the liquid is 2 inches deep.
Step-by-step explanation:
Since we have given that
Height = 9 inches
Diameter = 6 inches
Radius = 3 inches
So, 
Volume of cone is given by
By differentiating with respect to time t, we get that
Now, the liquid drips out the bottom of the filter at the constant rate of 4 cubic inches per second, ie 
and h = 2 inches deep.
Hence, level of the liquid dropping at 28.28 inch/second when the liquid is 2 inches deep.
Answer: 2.3
Step-by-step explanation:
9.2 is divided by 4 is 2.3 so the last quarter is 2.3
Answer:
87
Step-by-step explanation:
Do what's inside the paranethesis first
2+(9*3)=2+27=29
29*3=87
