Divide using synthetic division $$ ( x^{3}-6x^{2}-45x+50 ) \div ( x+5 ) $$
Answer
The synthetic division table is:
$$ \begin{array}{c|rrrr}-5&1&-6&-45&50\\& & -5& 55& \color{black}{-50} \\ \hline &\color{blue}{1}&\color{blue}{-11}&\color{blue}{10}&\color{orangered}{0} \end{array} $$The solution is:
$$ \frac{ x^{3}-6x^{2}-45x+50 }{ x+5 } = \color{blue}{x^{2}-11x+10} $$Explanation
Step 1 : Write down the coefficients of the dividend into division table. Put the zero from $ x + 5 = 0 $ ( $ x = \color{blue}{ -5 } $ ) at the left.
$$ \begin{array}{c|rrrr}\color{blue}{-5}&1&-6&-45&50\\& & & & \\ \hline &&&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrrr}-5&\color{orangered}{ 1 }&-6&-45&50\\& & & & \\ \hline &\color{orangered}{1}&&& \end{array} $$Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -5 } \cdot \color{blue}{ 1 } = \color{blue}{ -5 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-5}&1&-6&-45&50\\& & \color{blue}{-5} & & \\ \hline &\color{blue}{1}&&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ -6 } + \color{orangered}{ \left( -5 \right) } = \color{orangered}{ -11 } $
$$ \begin{array}{c|rrrr}-5&1&\color{orangered}{ -6 }&-45&50\\& & \color{orangered}{-5} & & \\ \hline &1&\color{orangered}{-11}&& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -5 } \cdot \color{blue}{ \left( -11 \right) } = \color{blue}{ 55 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-5}&1&-6&-45&50\\& & -5& \color{blue}{55} & \\ \hline &1&\color{blue}{-11}&& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ -45 } + \color{orangered}{ 55 } = \color{orangered}{ 10 } $
$$ \begin{array}{c|rrrr}-5&1&-6&\color{orangered}{ -45 }&50\\& & -5& \color{orangered}{55} & \\ \hline &1&-11&\color{orangered}{10}& \end{array} $$Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -5 } \cdot \color{blue}{ 10 } = \color{blue}{ -50 } $.
$$ \begin{array}{c|rrrr}\color{blue}{-5}&1&-6&-45&50\\& & -5& 55& \color{blue}{-50} \\ \hline &1&-11&\color{blue}{10}& \end{array} $$Step 7 : Add down last column: $ \color{orangered}{ 50 } + \color{orangered}{ \left( -50 \right) } = \color{orangered}{ 0 } $
$$ \begin{array}{c|rrrr}-5&1&-6&-45&\color{orangered}{ 50 }\\& & -5& 55& \color{orangered}{-50} \\ \hline &\color{blue}{1}&\color{blue}{-11}&\color{blue}{10}&\color{orangered}{0} \end{array} $$Bottom line represents the quotient $ \color{blue}{ x^{2}-11x+10 } $ with a remainder of $ \color{red}{ 0 } $.