Plz help with this problem!

x^4 + x^2 + 1

You cannot simplify this problem down anymore; it is at its simplest form.

Step-by-step explanation:

You cannot add together x^4 and x^2 due to the simple fact that they do not share similar exponents.

For example you could add together x^4 and x^4 to get 2x^4. But you cannot add x^4 and x^2.