The synthetic division table is:
$$ \begin{array}{c|rrrrr}0&1&-8&18&16&-40\\& & 0& 0& 0& \color{black}{0} \\ \hline &\color{blue}{1}&\color{blue}{-8}&\color{blue}{18}&\color{blue}{16}&\color{orangered}{-40} \end{array} $$The solution is:
$$ \frac{ x^{4}-8x^{3}+18x^{2}+16x-40 }{ x } = \color{blue}{x^{3}-8x^{2}+18x+16} \color{red}{~-~} \frac{ \color{red}{ 40 } }{ x } $$Step 1 : Write down the coefficients of the dividend into division table.Put the zero at the left.
$$ \begin{array}{c|rrrrr}\color{blue}{0}&1&-8&18&16&-40\\& & & & & \\ \hline &&&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrrr}0&\color{orangered}{ 1 }&-8&18&16&-40\\& & & & & \\ \hline &\color{orangered}{1}&&&& \end{array} $$Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 0 } \cdot \color{blue}{ 1 } = \color{blue}{ 0 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{0}&1&-8&18&16&-40\\& & \color{blue}{0} & & & \\ \hline &\color{blue}{1}&&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ -8 } + \color{orangered}{ 0 } = \color{orangered}{ -8 } $
$$ \begin{array}{c|rrrrr}0&1&\color{orangered}{ -8 }&18&16&-40\\& & \color{orangered}{0} & & & \\ \hline &1&\color{orangered}{-8}&&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 0 } \cdot \color{blue}{ \left( -8 \right) } = \color{blue}{ 0 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{0}&1&-8&18&16&-40\\& & 0& \color{blue}{0} & & \\ \hline &1&\color{blue}{-8}&&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ 18 } + \color{orangered}{ 0 } = \color{orangered}{ 18 } $
$$ \begin{array}{c|rrrrr}0&1&-8&\color{orangered}{ 18 }&16&-40\\& & 0& \color{orangered}{0} & & \\ \hline &1&-8&\color{orangered}{18}&& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 0 } \cdot \color{blue}{ 18 } = \color{blue}{ 0 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{0}&1&-8&18&16&-40\\& & 0& 0& \color{blue}{0} & \\ \hline &1&-8&\color{blue}{18}&& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ 16 } + \color{orangered}{ 0 } = \color{orangered}{ 16 } $
$$ \begin{array}{c|rrrrr}0&1&-8&18&\color{orangered}{ 16 }&-40\\& & 0& 0& \color{orangered}{0} & \\ \hline &1&-8&18&\color{orangered}{16}& \end{array} $$Step 8 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 0 } \cdot \color{blue}{ 16 } = \color{blue}{ 0 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{0}&1&-8&18&16&-40\\& & 0& 0& 0& \color{blue}{0} \\ \hline &1&-8&18&\color{blue}{16}& \end{array} $$Step 9 : Add down last column: $ \color{orangered}{ -40 } + \color{orangered}{ 0 } = \color{orangered}{ -40 } $
$$ \begin{array}{c|rrrrr}0&1&-8&18&16&\color{orangered}{ -40 }\\& & 0& 0& 0& \color{orangered}{0} \\ \hline &\color{blue}{1}&\color{blue}{-8}&\color{blue}{18}&\color{blue}{16}&\color{orangered}{-40} \end{array} $$Bottom line represents the quotient $ \color{blue}{ x^{3}-8x^{2}+18x+16 } $ with a remainder of $ \color{red}{ -40 } $.