Question
Subtract polynomials: $ \, \color{blue}{ 8x^3+4x^2-8x+3 } \, $ , $ \, \color{orangered}{ 8x^3-4x^2-x-9 }$.
Answer
$$ \left( \color{blue}{8x^3+4x^2-8x+3} \right) - \left( \color{orangered}{8x^3-4x^2-x-9} \right) = 8x^2-7x+12 $$
Explanation
Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrrr} & 8x^3 & 4x^2 & -8x & 3 \\ \color{red}{ - } & 8x^3 & -4x^2 & -x & -9 \\ \hline \end{array} $$Step 2: Change ALL the signs in the second row.
$$ \begin{array}{lrrrr} & 8x^3 & 4x^2 & -8x & 3 \\ \color{red}{ - } & -8x^3 & 4x^2 & x & 9 \\ \hline \end{array} $$Step 3: Combine like terms (add each column):
$$ \begin{array}{lrrrr} & 8x^3 & 4x^2 & -8x & 3 \\ \color{red}{ - } & -8x^3 & 4x^2 & x & 9 \\ \hline & 16x^3 & & -9x & -6 \end{array} $$This page was created using
Polynomial Operations Calculator