Question
Subtract polynomials: $ \, \color{blue}{ 9x^2-4 } \, $ , $ \, \color{orangered}{ 10x^2+9x-8 }$.
Answer
$$ \left( \color{blue}{9x^2-4} \right) - \left( \color{orangered}{10x^2+9x-8} \right) = -x^2-9x+4 $$
Explanation
Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrr} & 9x^2 & & -4 \\ \color{red}{ - } & 10x^2 & 9x & -8 \\ \hline \end{array} $$Step 2: Change ALL the signs in the second row.
$$ \begin{array}{lrrr} & 9x^2 & & -4 \\ \color{red}{ - } & -10x^2 & -9x & 8 \\ \hline \end{array} $$Step 3: Combine like terms (add each column):
$$ \begin{array}{lrrr} & 9x^2 & & -4 \\ \color{red}{ - } & -10x^2 & -9x & 8 \\ \hline & 19x^2 & 9x & -12 \end{array} $$This page was created using
Polynomial Operations Calculator