Which of the following shows that polynomials are closed under subtraction when polynomial 5x − 6 is subtracted from 3x2 − 6x + 2? 3x2 − 11x + 8 may or may not be a polynomial 3x2 − 11x + 8 will be a polynomial 3x2 − x + 4 may or may not be a polynomial 3x2 − x + 4 will be a polynomial tip: every 2 after 3x is an exponent.. so it would be 3x^2