Which polynomial is equal to (4x^2+3x-1)+(-3x^2-5x-8)?

In adding two polynomials, you have to remember that you can only add like terms. Like terms are terms that the same variable and exponent.

The expression would become like this:

4x^2 +3x – 1+ -3x^2 – 5x – 8

Now, you should add the like terms:

x^2 – 2x – 9