Answer:
CLAIMED
Step-by-step explanation:
Whenever you face the problem that deals with maxima or minima you should keep in mind that minima/maxima of a function is always a point where it's derivative is equal to zero.
To solve your problem we first need to find an equation of net benefits. Net benefits are expressed as a difference between total benefits and total cost. We can denote this function with B(y).
B(y)=b-c
B(y)=100y-18y²
Now that we have a net benefits function we need find it's derivate with respect to y.

Now we must find at which point this function is equal to zero.
0=100-36y
36y=100
y=2.8
Now that we know at which point our function reaches maxima we just plug that number back into our equation for net benefits and we get our answer.
B(2.8)=100(2.8)-18(2.8)²=138.88≈139.
One thing that always helps is to have your function graphed. It will give you a good insight into how your function behaves and allow you to identify minima/maxima points.
Answer:
2357.14
Step-by-step explanation:
x - .30x = 1500(1.10)
.7x = 1650
x = 2357.14
Make a list of all whole-number factors of 20:
1*20
2*10
4*5
The only reasonable set of dimensions out of the list is 4*5, so that is the answer.
R = 30 because r = 1,5,10,25
30/5+1=7
6+1=7