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.
As Tina only has 1/4 of a cake. For simplicity sake we can do the calculation with a whole cake and then multiply by four!
First it is stated that cake is divided into six pieces, giving us our first number.
So,
6 x 4 = 24
This means that each friend will get 1/24th of the whole cake.
Answer:
x^2-4x-12
Step-by-step explanation:
(x-6)(x+2)=x^2-6x+2x-12=x^2-4x-12
Answer:
350 ml
Step-by-step explanation:
70% of 500 ml = 0.7*500 ml = 350 ml