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