Answer: Our required formula becomes :

Step-by-step explanation:
Since we have given that

We need to write a formula for f(b) in terms of b So, it becomes

Hence, our required formula becomes :

You can use SAS, or Side Angle Side. Because BC equals EC and AC equals DC, you can get two sides. Also, angle BCA and DCE have the same angle measurement, so you can conclude, using SAS, that BA equals to ED. Also, you can also prove that these two triangles are congruent and that all of the angles are the same as well because all of the side lengths are equal.
To make a positive profit p(x)>0 we need to make:

Now we solve this for x:

We have:
a = -2
b = 7
c = -3
We will use formula for quadratic equation:

We got two solutions. One is fraction other is whole number. We will not consider fraction because the amount of muffins sold must be whole number. So our solution is:
x>3