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:
87
Step-by-step explanation:
Do what's inside the paranethesis first
2+(9*3)=2+27=29
29*3=87
If you look at all 4 of these tables. Exponential means a large increase or gradual increase so. With that in mind if you look at table 1, the y column only increases by 5. For B, the y column only increases by 1. For C, the y column increase by 4 then 8 then 16 then 32. Therefore it is exponential. For D it is consistently an increase of 8.
Hope this helps!
Start the line at 3 on the y-axis (vertical). then go down two boxes and to the right three & make a mark at that point. keep going down two and over three until the end of the graph. then just connect the marks.
45.5%, or 4.55, for 455/1000.
91/200