Answer:
9 inches of rainfall produces the maximum number of gnats.
Step-by-step explanation:
Given : 
To Find :How many inches of rainfall produces the maximum number of gnats?
Solution:

G(x) =The number of gnats in millions.
x denotes the length of rainfall
To Find the maximum length find the mid point of zeroes .Since parabolas are symmetrical, the x value of the max falls 1/2 way between the zeros.



So, x = 0 , x= 18
Now Formula of midpoint : 


Hence 9 inches of rainfall produces the maximum number of gnats.
Rectangular prism and cylinder
The pie it’s self is 6.75, the ice cream is 1.25 and that makes 8 dollars per person which totals up to 32
The total revenue of the function is the product of the quantity and the price
The total revenue in terms of P is TR = 20P - 0.01P^2
<h3>How to determine the total revenue?</h3>
The demand and the cost functions are given as:
Quantity function, Q = 20 - 0.01P
Cost function, C(Q)=60+6Q
The total revenue is calculated as:
TR = Q * P
Substitute Q = 20 - 0.01P in the above equation
TR = P * [20 - 0.01P]
Evaluate the product
TR = 20P - 0.01P^2
Hence, the total revenue in terms of P is TR = 20P - 0.01P^2
Read more about total revenue at:
brainly.com/question/25623677
13-4x=1-x
13=4x+x=1-x+x
13-3x=1
13-1-3x=1-1
12-3x=0
12=3x
12/3=3x/3
4=x
Therefore, x=4