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: 54 cm²
Step-by-step explanation: In this problem, we're asked to find the area of the trapezoid shown. A trapezoid is a quadrilateral with one pair of parallel sides.
The formula for the area of a trapezoid is shown below.

The <em>b's</em> represent the bases which are the parallel sides and <em>h</em> is the height.
So in the trapezoid shown, the bases are 6 cm and 12 cm and the height is 6 cm. Plugging this information into the formula, we have
.
Next, the order of operations tell us that we must simplify inside the parentheses first. 6 cm + 12 cm is 18 cm and we have
.
is 9 cm and we have 9 cm · 6 cm of 54 cm²
So the area of the trapezoid shown is 54 cm².
Answer: The answer is P'(7, 17.5) and Q'(7, 3.5).
Step-by-step explanation: Given that a line segment PQ is dilated with a scale factor of 3.5 where origin is the centre of dilation.
The end points of segment PQ are P(2, 5) and Q(2, 1).
Therefore, after dilation, the coordinates of the end points become
Thus, the coordinates of P' are (7, 17.5) and the co-ordinates of Q' are (7, 3.5).
Well if it is touching the x-axis, the radius is 3 units.
C = 2 * pi * r = (2)(3.14)(3) = 18.8 or so