The synthetic division table is:
$$ \begin{array}{c|rrrrr}-3&1&0&-4&3&3\\& & -3& 9& -15& \color{black}{36} \\ \hline &\color{blue}{1}&\color{blue}{-3}&\color{blue}{5}&\color{blue}{-12}&\color{orangered}{39} \end{array} $$The solution is:
$$ \frac{ x^{4}-4x^{2}+3x+3 }{ x+3 } = \color{blue}{x^{3}-3x^{2}+5x-12} ~+~ \frac{ \color{red}{ 39 } }{ x+3 } $$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.
$$ \begin{array}{c|rrrrr}\color{blue}{-3}&1&0&-4&3&3\\& & & & & \\ \hline &&&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrrr}-3&\color{orangered}{ 1 }&0&-4&3&3\\& & & & & \\ \hline &\color{orangered}{1}&&&& \end{array} $$Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -3 } \cdot \color{blue}{ 1 } = \color{blue}{ -3 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{-3}&1&0&-4&3&3\\& & \color{blue}{-3} & & & \\ \hline &\color{blue}{1}&&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ 0 } + \color{orangered}{ \left( -3 \right) } = \color{orangered}{ -3 } $
$$ \begin{array}{c|rrrrr}-3&1&\color{orangered}{ 0 }&-4&3&3\\& & \color{orangered}{-3} & & & \\ \hline &1&\color{orangered}{-3}&&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -3 } \cdot \color{blue}{ \left( -3 \right) } = \color{blue}{ 9 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{-3}&1&0&-4&3&3\\& & -3& \color{blue}{9} & & \\ \hline &1&\color{blue}{-3}&&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ -4 } + \color{orangered}{ 9 } = \color{orangered}{ 5 } $
$$ \begin{array}{c|rrrrr}-3&1&0&\color{orangered}{ -4 }&3&3\\& & -3& \color{orangered}{9} & & \\ \hline &1&-3&\color{orangered}{5}&& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -3 } \cdot \color{blue}{ 5 } = \color{blue}{ -15 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{-3}&1&0&-4&3&3\\& & -3& 9& \color{blue}{-15} & \\ \hline &1&-3&\color{blue}{5}&& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ 3 } + \color{orangered}{ \left( -15 \right) } = \color{orangered}{ -12 } $
$$ \begin{array}{c|rrrrr}-3&1&0&-4&\color{orangered}{ 3 }&3\\& & -3& 9& \color{orangered}{-15} & \\ \hline &1&-3&5&\color{orangered}{-12}& \end{array} $$Step 8 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -3 } \cdot \color{blue}{ \left( -12 \right) } = \color{blue}{ 36 } $.
$$ \begin{array}{c|rrrrr}\color{blue}{-3}&1&0&-4&3&3\\& & -3& 9& -15& \color{blue}{36} \\ \hline &1&-3&5&\color{blue}{-12}& \end{array} $$Step 9 : Add down last column: $ \color{orangered}{ 3 } + \color{orangered}{ 36 } = \color{orangered}{ 39 } $
$$ \begin{array}{c|rrrrr}-3&1&0&-4&3&\color{orangered}{ 3 }\\& & -3& 9& -15& \color{orangered}{36} \\ \hline &\color{blue}{1}&\color{blue}{-3}&\color{blue}{5}&\color{blue}{-12}&\color{orangered}{39} \end{array} $$Bottom line represents the quotient $ \color{blue}{ x^{3}-3x^{2}+5x-12 } $ with a remainder of $ \color{red}{ 39 } $.