1.) find all of the #x³ and there is only one and that is -x³ so that limits the problem to B or D.
2.) now you find all of the #x² and there are three of them being 10x², -x², and 4x². Now that you have identified them you will add them together to get a sum of 13x²
you don't have to do anymore of the question because D does not have 13x² so it is B.
A, C, and D all do because if you were to hold a pencil up vertically, the line would only intersect it once, if it intersected more, it is not a function
