1) Combining like terms, we get x^2 + 5x, which is a binomial.
2) Combining like terms, we get x^3 + 3x^2, which is a binomial.
3) Combining like terms, we get 4x^3 + x^2 - x, which is a trinomial.
4) I can't answer this because there's an asterisk in place of the exponent.