Question
Subtract polynomials: $ \, \color{blue}{ 3r^2+2r-7 } \, $ , $ \, \color{orangered}{ -4r^3+2r+4 }$.
Answer
$$ \left( \color{blue}{3r^2+2r-7} \right) - \left( \color{orangered}{-4r^3+2r+4} \right) = 4r^3+3r^2-11 $$
Explanation
Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrrr} & & 3r^2 & 2r & -7 \\ \color{red}{ - } & -4r^3 & & 2r & 4 \\ \hline \end{array} $$Step 2: Change ALL the signs in the second row.
$$ \begin{array}{lrrrr} & & 3r^2 & 2r & -7 \\ \color{red}{ - } & 4r^3 & & -2r & -4 \\ \hline \end{array} $$Step 3: Combine like terms (add each column):
$$ \begin{array}{lrrrr} & & 3r^2 & 2r & -7 \\ \color{red}{ - } & 4r^3 & & -2r & -4 \\ \hline & -4r^3 & 3r^2 & 4r & -3 \end{array} $$This page was created using
Polynomial Operations Calculator