Question
Subtract polynomials: $ \, \color{blue}{ 9x^3+5x^2-x-9 } \, $ , $ \, \color{orangered}{ x^2-9x+4 }$.
Answer
$$ \left( \color{blue}{9x^3+5x^2-x-9} \right) - \left( \color{orangered}{x^2-9x+4} \right) = 9x^3+4x^2+8x-13 $$
Explanation
Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrrr} & 9x^3 & 5x^2 & -x & -9 \\ \color{red}{ - } & & x^2 & -9x & 4 \\ \hline \end{array} $$Step 2: Change ALL the signs in the second row.
$$ \begin{array}{lrrrr} & 9x^3 & 5x^2 & -x & -9 \\ \color{red}{ - } & & -x^2 & 9x & -4 \\ \hline \end{array} $$Step 3: Combine like terms (add each column):
$$ \begin{array}{lrrrr} & 9x^3 & 5x^2 & -x & -9 \\ \color{red}{ - } & & -x^2 & 9x & -4 \\ \hline & 9x^3 & 6x^2 & -10x & -5 \end{array} $$This page was created using
Polynomial Operations Calculator