8. [-/1 Points] DETAILS MY NOTES TGEIALG6 5.5.046. Use vertical form to add the polynomials. (Simplify your answer completely.) \[ \begin{array}{l} 9 x^{3}+7 x^{2}-9 x+2 \\ 9 x^{3}-7 x^{2}-x-7 \\ \hline \end{array} \] \( \square \) SUBMIT ANSWER

To add the polynomials using vertical form, you align like terms: \[ \begin{array}{r} 9x^3 + 7x^2 - 9x + 2 \\ + 9x^3 - 7x^2 - x - 7 \\ \hline \end{array} \] Now, let's perform the addition. Start from the top: 1. For \(x^3\): \(9x^3 + 9x^3 = 18x^3\) 2. For \(x^2\): \(7x^2 - 7x^2 = 0\) 3. For \(x\): \(-9x - x = -10x\) 4. For the constant: \(2 - 7 = -5\) Putting it all together, you get: \[ 18x^3 - 10x - 5 \] The final simplified expression is \(18x^3 - 10x - 5\).