Question

Use a vertical format or a horizontal format to add or subtract. $$\left(-9 z^{3}-3 z\right)+\left(13 z-8 z^{2}\right)$$

Short answer

The result of the addition is \( -9z^3 - 8z^2 + 10z \)

Step-by-step solution

Organize the terms

Rearrange the terms in each polynomial in descending order according to their powers. Then line up like terms vertically. For example: \[ \begin{array}{r} -9z^3 + 0z^2 -3z \ +\ 0z^3 -8z^2 + 13z \end{array}\]

Combine coefficients

Add the coefficients of the like terms in the polynomials. So we get \[ -9z^3 - 8z^2 + 10z \]