I need help figuring out this problem:

Use Descartes' Rule of Signs to analyze the number of positive and negative real roots and the number of non-real roots of the function:

http://hosted.webwork.rochester.edu/...04137e56c1.png

There are at least __ and at most ___ positive real roots.

There are at least___ and at most___ negative real roots.

There are at least ___and at most ____ non-real roots.