First, and most important, you must know what the question is. You haven't told us what the question is, and a gray cloud hangs like a dark mist over the problem, giving the unmistakable impression that you're not too sure of it yourself.
You would use the Pythagorean theorem and plug it in
I’m pretty sure
8. would be false because BK would be 12 where as DF is 10.8
9. is true
First put it in decreasing power according to x.
x^4-5x+8+x^2
=x^4+x^2-5x+8
Now this question is asking what is the highest degree of x you see in this function.
4 of course.
Therefore the answer to his question is degree of 4.
Done!