More Finding Zeros of a Polynomial

Hello, all. I have three problems related to finding zeros of a polynomial.

First problem:

I need to find the zeros of the following polynomial so that I can graph it:

Using synthetic division, I found two zeros and so now I have:

I'm not sure how to factor to find the remaining zeros.

Second problem:

I need to find the zeros of the following polynomial so that I can graph it:

Using synthetic division, I found one zero, so now I have:

I'm pretty sure that can't be factored, so what does this mean for the graph?

Final problem:

I need to find the zeros of the following polynomial so that I can graph it:

I used synthetic division to find:

Again, it doesn't seem that I can factor any further. What does this mean for the graph?

Thanks again!