Greetings!
Yes, the degree on a monomial can be negative:
Example:

This is equal to:

Hope this helps.
-Benjamin
If u add 125 times 8 it will equal 1000
becouse

then

you also can combine it (if this is what are you looking for..)

or any other combination like:

or:
The third one down
Because the best line of fit is a line that goes between the plotted points and it HAS to be a straight line and most of the points close to the line
I believe it is B. I could be wrong but I am hoping that you get it right