When simplified, which of the following expressions has a coefficient of 5?

-4x - 9x
-4x + 9x
4x - 9x
4x - (-9x)

Select the correct answer from each drop-down menu. consider the following polynomials equations. 3x^2(x-1) and -3x^3+ 4x^2-2x+1 perform each operation and determine if the result is a polynomial. is the result of a + b a polynomial? yes or no is the result of a - b a polynomial? yes or no is the result of a · b a polynomial? yes or no