Solve not working?

Every time I try to use the solve function in Mathematica 10 for Students, I get the error “0 is not a valid variable”. Here’s what I’ve been entering:

Solve[2x^3 + x^2 + 2 == 0, x]

I also tried to enter an example of the solve function from the Mathematica documentation, and that also did not work.

Strange, it works in Mathematica 10 Home Edition. Are you sure you typed it in as you’ve shown?

Usually, this kind of error is the result of having set x=0 earlier in the session.

John is right, thank you very much. I fixed it.