Divide using synthetic division $$ ( x^{5}-6x^{3}+x ) \div ( x+1 ) $$
Answer
The synthetic division table is:
$$ \begin{array}{c|rrrrrr}-1&1&0&-6&0&1&0\\& & -1& 1& 5& -5& \color{black}{4} \\ \hline &\color{blue}{1}&\color{blue}{-1}&\color{blue}{-5}&\color{blue}{5}&\color{blue}{-4}&\color{orangered}{4} \end{array} $$The solution is:
$$ \frac{ x^{5}-6x^{3}+x }{ x+1 } = \color{blue}{x^{4}-x^{3}-5x^{2}+5x-4} ~+~ \frac{ \color{red}{ 4 } }{ x+1 } $$Explanation
Step 1 : Write down the coefficients of the dividend into division table. Put the zero from $ x + 1 = 0 $ ( $ x = \color{blue}{ -1 } $ ) at the left.
$$ \begin{array}{c|rrrrrr}\color{blue}{-1}&1&0&-6&0&1&0\\& & & & & & \\ \hline &&&&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrrrr}-1&\color{orangered}{ 1 }&0&-6&0&1&0\\& & & & & & \\ \hline &\color{orangered}{1}&&&&& \end{array} $$Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -1 } \cdot \color{blue}{ 1 } = \color{blue}{ -1 } $.
$$ \begin{array}{c|rrrrrr}\color{blue}{-1}&1&0&-6&0&1&0\\& & \color{blue}{-1} & & & & \\ \hline &\color{blue}{1}&&&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ 0 } + \color{orangered}{ \left( -1 \right) } = \color{orangered}{ -1 } $
$$ \begin{array}{c|rrrrrr}-1&1&\color{orangered}{ 0 }&-6&0&1&0\\& & \color{orangered}{-1} & & & & \\ \hline &1&\color{orangered}{-1}&&&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -1 } \cdot \color{blue}{ \left( -1 \right) } = \color{blue}{ 1 } $.
$$ \begin{array}{c|rrrrrr}\color{blue}{-1}&1&0&-6&0&1&0\\& & -1& \color{blue}{1} & & & \\ \hline &1&\color{blue}{-1}&&&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ -6 } + \color{orangered}{ 1 } = \color{orangered}{ -5 } $
$$ \begin{array}{c|rrrrrr}-1&1&0&\color{orangered}{ -6 }&0&1&0\\& & -1& \color{orangered}{1} & & & \\ \hline &1&-1&\color{orangered}{-5}&&& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -1 } \cdot \color{blue}{ \left( -5 \right) } = \color{blue}{ 5 } $.
$$ \begin{array}{c|rrrrrr}\color{blue}{-1}&1&0&-6&0&1&0\\& & -1& 1& \color{blue}{5} & & \\ \hline &1&-1&\color{blue}{-5}&&& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ 0 } + \color{orangered}{ 5 } = \color{orangered}{ 5 } $
$$ \begin{array}{c|rrrrrr}-1&1&0&-6&\color{orangered}{ 0 }&1&0\\& & -1& 1& \color{orangered}{5} & & \\ \hline &1&-1&-5&\color{orangered}{5}&& \end{array} $$Step 8 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -1 } \cdot \color{blue}{ 5 } = \color{blue}{ -5 } $.
$$ \begin{array}{c|rrrrrr}\color{blue}{-1}&1&0&-6&0&1&0\\& & -1& 1& 5& \color{blue}{-5} & \\ \hline &1&-1&-5&\color{blue}{5}&& \end{array} $$Step 9 : Add down last column: $ \color{orangered}{ 1 } + \color{orangered}{ \left( -5 \right) } = \color{orangered}{ -4 } $
$$ \begin{array}{c|rrrrrr}-1&1&0&-6&0&\color{orangered}{ 1 }&0\\& & -1& 1& 5& \color{orangered}{-5} & \\ \hline &1&-1&-5&5&\color{orangered}{-4}& \end{array} $$Step 10 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -1 } \cdot \color{blue}{ \left( -4 \right) } = \color{blue}{ 4 } $.
$$ \begin{array}{c|rrrrrr}\color{blue}{-1}&1&0&-6&0&1&0\\& & -1& 1& 5& -5& \color{blue}{4} \\ \hline &1&-1&-5&5&\color{blue}{-4}& \end{array} $$Step 11 : Add down last column: $ \color{orangered}{ 0 } + \color{orangered}{ 4 } = \color{orangered}{ 4 } $
$$ \begin{array}{c|rrrrrr}-1&1&0&-6&0&1&\color{orangered}{ 0 }\\& & -1& 1& 5& -5& \color{orangered}{4} \\ \hline &\color{blue}{1}&\color{blue}{-1}&\color{blue}{-5}&\color{blue}{5}&\color{blue}{-4}&\color{orangered}{4} \end{array} $$Bottom line represents the quotient $ \color{blue}{ x^{4}-x^{3}-5x^{2}+5x-4 } $ with a remainder of $ \color{red}{ 4 } $.