Question
Subtract polynomials: $ \, \color{blue}{ 9x^3+4x^2+8x+7 } \, $ , $ \, \color{orangered}{ 5x^3+2x^2+x+7 }$.
Answer
$$ \left( \color{blue}{9x^3+4x^2+8x+7} \right) - \left( \color{orangered}{5x^3+2x^2+x+7} \right) = 4x^3+2x^2+7x $$
Explanation
Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrrr} & 9x^3 & 4x^2 & 8x & 7 \\ \color{red}{ - } & 5x^3 & 2x^2 & x & 7 \\ \hline \end{array} $$Step 2: Change ALL the signs in the second row.
$$ \begin{array}{lrrrr} & 9x^3 & 4x^2 & 8x & 7 \\ \color{red}{ - } & -5x^3 & -2x^2 & -x & -7 \\ \hline \end{array} $$Step 3: Combine like terms (add each column):
$$ \begin{array}{lrrrr} & 9x^3 & 4x^2 & 8x & 7 \\ \color{red}{ - } & -5x^3 & -2x^2 & -x & -7 \\ \hline & 14x^3 & 6x^2 & 9x & 14 \end{array} $$This page was created using
Polynomial Operations Calculator