Divide using synthetic division $$ ( x^{3}-14x^{2}+35x+50 ) \div ( x+1 ) $$
Answer
The synthetic division table is:
$$ \begin{array}{c|rrrr}-1&1&-14&35&50\\& & -1& 15& \color{black}{-50} \\ \hline &\color{blue}{1}&\color{blue}{-15}&\color{blue}{50}&\color{orangered}{0} \end{array} $$The solution is:
$$ \frac{ x^{3}-14x^{2}+35x+50 }{ x+1 } = \color{blue}{x^{2}-15x+50} $$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.
$$ \begin{array}{c|rrrr}\color{blue}{-1}&1&-14&35&50\\& & & & \\ \hline &&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrr}-1&\color{orangered}{ 1 }&-14&35&50\\& & & & \\ \hline &\color{orangered}{1}&&& \end{array} $$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 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-1}&1&-14&35&50\\& & \color{blue}{-1} & & \\ \hline &\color{blue}{1}&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ -14 } + \color{orangered}{ \left( -1 \right) } = \color{orangered}{ -15 } $
$$ \begin{array}{c|rrrr}-1&1&\color{orangered}{ -14 }&35&50\\& & \color{orangered}{-1} & & \\ \hline &1&\color{orangered}{-15}&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -1 } \cdot \color{blue}{ \left( -15 \right) } = \color{blue}{ 15 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-1}&1&-14&35&50\\& & -1& \color{blue}{15} & \\ \hline &1&\color{blue}{-15}&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ 35 } + \color{orangered}{ 15 } = \color{orangered}{ 50 } $
$$ \begin{array}{c|rrrr}-1&1&-14&\color{orangered}{ 35 }&50\\& & -1& \color{orangered}{15} & \\ \hline &1&-15&\color{orangered}{50}& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -1 } \cdot \color{blue}{ 50 } = \color{blue}{ -50 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-1}&1&-14&35&50\\& & -1& 15& \color{blue}{-50} \\ \hline &1&-15&\color{blue}{50}& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ 50 } + \color{orangered}{ \left( -50 \right) } = \color{orangered}{ 0 } $
$$ \begin{array}{c|rrrr}-1&1&-14&35&\color{orangered}{ 50 }\\& & -1& 15& \color{orangered}{-50} \\ \hline &\color{blue}{1}&\color{blue}{-15}&\color{blue}{50}&\color{orangered}{0} \end{array} $$Bottom line represents the quotient $ \color{blue}{ x^{2}-15x+50 } $ with a remainder of $ \color{red}{ 0 } $.