So, you need to show that they do not withhold the subspace axioms.
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1. What conditions would these sets need to fill in order to be vector subspaces?
2. Now that you've answered q1, it should be easy to find an example (even the same example for all three of them) that shows they are not subspaces.
I'll give you a hint. There is one example that works for all of them, and it is very simple. You do not even need to give a specific polynomial. Think about it this way: Say you are given some polynomial $\displaystyle p(x) \in E_1$. How can you change $\displaystyle p(x)$, to get $\displaystyle q(x)$ such that $\displaystyle p(x) + q(x) \notin E_1$?