Subtract polynomials: $ \, \color{blue}{ 7x^2-9x+7 } \, $ , $ \, \color{orangered}{ 8x^2-6x-9 }$.
Answer
$$ \left( \color{blue}{7x^2-9x+7} \right) - \left( \color{orangered}{8x^2-6x-9} \right) = -x^2-3x+16 $$
Explanation
Step 1: Write second polynomial below the first one. Making sure like terms are lined up.
$$ \begin{array}{lrrr} & 7x^2 & -9x & 7 \\ \color{red}{ - } & 8x^2 & -6x & -9 \\ \hline \end{array} $$Step 2: Change ALL the signs in the second row.
$$ \begin{array}{lrrr} & 7x^2 & -9x & 7 \\ \color{red}{ - } & -8x^2 & 6x & 9 \\ \hline \end{array} $$Step 3: Combine like terms (add each column):
$$ \begin{array}{lrrr} & 7x^2 & -9x & 7 \\ \color{red}{ - } & -8x^2 & 6x & 9 \\ \hline & 15x^2 & -15x & -2 \end{array} $$This page was created using
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