For this case we have the following quadratic functions:
Revenue: 
Cost: 
Then, we observe that the profit is given by the following mathematical relationship:

Substituting values we have:

Making the corresponding calculations we have:

Answer:
An expression that represents the profit is:

Area= base x height
So, the base is 9 1/4 and the height is 18 feet
so, the Area= 9 1/4 x 18
9 1/4 x 18
= 166.5
You do 90-45 bc the whole angel must equal 90
Answer:
Option B. 
Step-by-step explanation:
we know that
The formula to solve a quadratic equation of the form
is equal to
in this problem we have

so
substitute in the formula
Remember that

substitute
