Divide using synthetic division $$ ( x^{3}-14x^{2}-7x-4 ) \div ( x+3 ) $$
Answer
The synthetic division table is:
$$ \begin{array}{c|rrrr}-3&1&-14&-7&-4\\& & -3& 51& \color{black}{-132} \\ \hline &\color{blue}{1}&\color{blue}{-17}&\color{blue}{44}&\color{orangered}{-136} \end{array} $$The solution is:
$$ \frac{ x^{3}-14x^{2}-7x-4 }{ x+3 } = \color{blue}{x^{2}-17x+44} \color{red}{~-~} \frac{ \color{red}{ 136 } }{ x+3 } $$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.
$$ \begin{array}{c|rrrr}\color{blue}{-3}&1&-14&-7&-4\\& & & & \\ \hline &&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrr}-3&\color{orangered}{ 1 }&-14&-7&-4\\& & & & \\ \hline &\color{orangered}{1}&&& \end{array} $$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 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-3}&1&-14&-7&-4\\& & \color{blue}{-3} & & \\ \hline &\color{blue}{1}&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ -14 } + \color{orangered}{ \left( -3 \right) } = \color{orangered}{ -17 } $
$$ \begin{array}{c|rrrr}-3&1&\color{orangered}{ -14 }&-7&-4\\& & \color{orangered}{-3} & & \\ \hline &1&\color{orangered}{-17}&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -3 } \cdot \color{blue}{ \left( -17 \right) } = \color{blue}{ 51 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-3}&1&-14&-7&-4\\& & -3& \color{blue}{51} & \\ \hline &1&\color{blue}{-17}&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ -7 } + \color{orangered}{ 51 } = \color{orangered}{ 44 } $
$$ \begin{array}{c|rrrr}-3&1&-14&\color{orangered}{ -7 }&-4\\& & -3& \color{orangered}{51} & \\ \hline &1&-17&\color{orangered}{44}& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -3 } \cdot \color{blue}{ 44 } = \color{blue}{ -132 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-3}&1&-14&-7&-4\\& & -3& 51& \color{blue}{-132} \\ \hline &1&-17&\color{blue}{44}& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ -4 } + \color{orangered}{ \left( -132 \right) } = \color{orangered}{ -136 } $
$$ \begin{array}{c|rrrr}-3&1&-14&-7&\color{orangered}{ -4 }\\& & -3& 51& \color{orangered}{-132} \\ \hline &\color{blue}{1}&\color{blue}{-17}&\color{blue}{44}&\color{orangered}{-136} \end{array} $$Bottom line represents the quotient $ \color{blue}{ x^{2}-17x+44 } $ with a remainder of $ \color{red}{ -136 } $.