Answer:
43.20
Step-by-step explanation:
I hope this is right !
Since

is negative, it doesn't have any real roots.
Answer:

Step-by-step explanation:
Arithmetic sequence:
In an arithmetic sequence, the difference between consecutive terms is always the same, and is called common difference.
The nth term is given by the following equation:

In which
is the first term and d is the common difference.
First term is 9 common difference is -2
This means that 
So, the nth term is given by:



Graph D, because no x-value repeats and it passes the vertical line test.