Which of the following is a Polynomial? *
1 point
x^4 - x^3 - 7x^2 + x + 6
x^4 - x^(-3) - 7x^2 + x + 6
x^4 - x^3 - 7x^(1/2) + x + 6
1/x - x^3 - 7x^2 + x + 6