Answer:
it's 81 cents
Step-by-step explanation:

You should try to restate the question more descriptively.
Answer: 8m
Step-by-step explanation:
Anything raised to 0 is 1.
8m*1
Multiply 8 by 1.
8m
Answer:
$32.10
Step-by-step explanation:
If you have sales tax, you would first convert the percentage to decimal, or 0.07. Then you would take this number, and add it to one before you multiply it by the price of the sweatshirt. This makes sure that you're not just calculating the sales tax, but the overall price of the shirt. So if you multiply:
30 x 1.07 = 32.1
Add the units, and you get $32.10
Hope this helps!
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.