Question
Subtract polynomials: $ \, \color{blue}{ 3x^3+9x+7 } \, $ , $ \, \color{orangered}{ 2x^2+4x+13 }$.
Answer
$$ \left( \color{blue}{3x^3+9x+7} \right) - \left( \color{orangered}{2x^2+4x+13} \right) = 3x^3-2x^2+5x-6 $$
Explanation
Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrrr} & 3x^3 & & 9x & 7 \\ \color{red}{ - } & & 2x^2 & 4x & 13 \\ \hline \end{array} $$Step 2: Change ALL the signs in the second row.
$$ \begin{array}{lrrrr} & 3x^3 & & 9x & 7 \\ \color{red}{ - } & & -2x^2 & -4x & -13 \\ \hline \end{array} $$Step 3: Combine like terms (add each column):
$$ \begin{array}{lrrrr} & 3x^3 & & 9x & 7 \\ \color{red}{ - } & & -2x^2 & -4x & -13 \\ \hline & 3x^3 & 2x^2 & 13x & 20 \end{array} $$This page was created using
Polynomial Operations Calculator