Divide using synthetic division $$ ( -2x^{3}-4x^{2}-9 ) \div ( -1 ) $$
The synthetic division table is:
$$ \begin{array}{c|rrrr}0&-2&-4&0&-9\\& & 0& 0& \color{black}{0} \\ \hline &\color{blue}{-2}&\color{blue}{-4}&\color{blue}{0}&\color{orangered}{-9} \end{array} $$The solution is:
$$ \dfrac{ -2x^{3}-4x^{2}-9 }{ x } = \color{blue}{-2x^{2}-4x} \color{red}{~-~} \dfrac{ \color{red}{ 9 } }{ x } $$Step 1 : Write down the coefficients of the dividend into division table.Put the zero at the left.
$$ \begin{array}{c|rrrr}\color{blue}{0}&-2&-4&0&-9\\& & & & \\ \hline &&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrr}0&\color{orangered}{ -2 }&-4&0&-9\\& & & & \\ \hline &\color{orangered}{-2}&&& \end{array} $$Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 0 } \cdot \color{blue}{ \left( -2 \right) } = \color{blue}{ 0 } $.
$$ \begin{array}{c|rrrr}\color{blue}{0}&-2&-4&0&-9\\& & \color{blue}{0} & & \\ \hline &\color{blue}{-2}&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ -4 } + \color{orangered}{ 0 } = \color{orangered}{ -4 } $
$$ \begin{array}{c|rrrr}0&-2&\color{orangered}{ -4 }&0&-9\\& & \color{orangered}{0} & & \\ \hline &-2&\color{orangered}{-4}&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 0 } \cdot \color{blue}{ \left( -4 \right) } = \color{blue}{ 0 } $.
$$ \begin{array}{c|rrrr}\color{blue}{0}&-2&-4&0&-9\\& & 0& \color{blue}{0} & \\ \hline &-2&\color{blue}{-4}&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ 0 } + \color{orangered}{ 0 } = \color{orangered}{ 0 } $
$$ \begin{array}{c|rrrr}0&-2&-4&\color{orangered}{ 0 }&-9\\& & 0& \color{orangered}{0} & \\ \hline &-2&-4&\color{orangered}{0}& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 0 } \cdot \color{blue}{ 0 } = \color{blue}{ 0 } $.
$$ \begin{array}{c|rrrr}\color{blue}{0}&-2&-4&0&-9\\& & 0& 0& \color{blue}{0} \\ \hline &-2&-4&\color{blue}{0}& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ -9 } + \color{orangered}{ 0 } = \color{orangered}{ -9 } $
$$ \begin{array}{c|rrrr}0&-2&-4&0&\color{orangered}{ -9 }\\& & 0& 0& \color{orangered}{0} \\ \hline &\color{blue}{-2}&\color{blue}{-4}&\color{blue}{0}&\color{orangered}{-9} \end{array} $$Bottom line represents the quotient $ \color{blue}{ -2x^{2}-4x } $ with a remainder of $ \color{red}{ -9 } $.