Answer:
6400
Step-by-step explanation:
so every 5 hours it gains 800 bacteria so 4800+800=5600 (hour 10)
and 5600+800=6400 (hour 15)
To find the zeros of this function, we must first set the entire function equal to 0
f(x) = x² - 2x - 15 = 0
Since this is a quadratic function, we must use the quadratic formula, which is:

Let's assign a, b, and c using our first function
x² means a = 1 (because it could be written as 1x²)
-2x means b = -2
-15 means c = -15
Now let's plug those in:

which simplifies to:

Simplified further:


And divide it by the 2 on the bottom gives us:

2+4 = 6
2-4 = -2
So the zeros of this function are
-2 and
6
TeX rendering has been iffy at best on this site for the past few days, at least in my experience. I've attached a solution below.
We can solve this by first finding the diameter of the two semicircles. We know that the width of the rectangle is 27 inches, which also happens to be the diameter of the circle.
The circumference of a circle is 2πr or πd. The problem says that it is a semicircle, however, it says that there are two of them. Since the two semicircles are the same size, we know that they can combine to form one circle, so we can just find the circumference of one circle to account for both of the semicircles:
C=27π inches
We also know that the length of the rectangle is 60 inches. We only want to find the perimeter of the frame, so we don't have to account for the widths of the rectangle because it is inside the frame. Therefore, the two sides of the rectangle together are 120 inches. Now we can add this to the circumference we found:
120+27π inches or 204.78 inches (depends on what your teacher is asking for)