Divide using synthetic division $$ ( -2x^{3}-5x^{2}-3x+9 ) \div ( x-3 ) $$
Answer
The synthetic division table is:
$$ \begin{array}{c|rrrr}3&-2&-5&-3&9\\& & -6& -33& \color{black}{-108} \\ \hline &\color{blue}{-2}&\color{blue}{-11}&\color{blue}{-36}&\color{orangered}{-99} \end{array} $$The solution is:
$$ \frac{ -2x^{3}-5x^{2}-3x+9 }{ x-3 } = \color{blue}{-2x^{2}-11x-36} \color{red}{~-~} \frac{ \color{red}{ 99 } }{ x-3 } $$Explanation
Step 1 : Write down the coefficients of the dividend into division table. Put the zero from $ x -3 = 0 $ ( $ x = \color{blue}{ 3 } $ ) at the left.
$$ \begin{array}{c|rrrr}\color{blue}{3}&-2&-5&-3&9\\& & & & \\ \hline &&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrr}3&\color{orangered}{ -2 }&-5&-3&9\\& & & & \\ \hline &\color{orangered}{-2}&&& \end{array} $$Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 3 } \cdot \color{blue}{ \left( -2 \right) } = \color{blue}{ -6 } $.
$$ \begin{array}{c|rrrr}\color{blue}{3}&-2&-5&-3&9\\& & \color{blue}{-6} & & \\ \hline &\color{blue}{-2}&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ -5 } + \color{orangered}{ \left( -6 \right) } = \color{orangered}{ -11 } $
$$ \begin{array}{c|rrrr}3&-2&\color{orangered}{ -5 }&-3&9\\& & \color{orangered}{-6} & & \\ \hline &-2&\color{orangered}{-11}&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 3 } \cdot \color{blue}{ \left( -11 \right) } = \color{blue}{ -33 } $.
$$ \begin{array}{c|rrrr}\color{blue}{3}&-2&-5&-3&9\\& & -6& \color{blue}{-33} & \\ \hline &-2&\color{blue}{-11}&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ -3 } + \color{orangered}{ \left( -33 \right) } = \color{orangered}{ -36 } $
$$ \begin{array}{c|rrrr}3&-2&-5&\color{orangered}{ -3 }&9\\& & -6& \color{orangered}{-33} & \\ \hline &-2&-11&\color{orangered}{-36}& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 3 } \cdot \color{blue}{ \left( -36 \right) } = \color{blue}{ -108 } $.
$$ \begin{array}{c|rrrr}\color{blue}{3}&-2&-5&-3&9\\& & -6& -33& \color{blue}{-108} \\ \hline &-2&-11&\color{blue}{-36}& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ 9 } + \color{orangered}{ \left( -108 \right) } = \color{orangered}{ -99 } $
$$ \begin{array}{c|rrrr}3&-2&-5&-3&\color{orangered}{ 9 }\\& & -6& -33& \color{orangered}{-108} \\ \hline &\color{blue}{-2}&\color{blue}{-11}&\color{blue}{-36}&\color{orangered}{-99} \end{array} $$Bottom line represents the quotient $ \color{blue}{ -2x^{2}-11x-36 } $ with a remainder of $ \color{red}{ -99 } $.