Check if $ x+2 $ is a factor of $ x^{3}-2x^{2}-23x-60 $.

The synthetic division table is:

$$ \begin{array}{c|rrrr}-2&1&-2&-23&-60\\& & -2& 8& \color{black}{30} \\ \hline &\color{blue}{1}&\color{blue}{-4}&\color{blue}{-15}&\color{orangered}{-30} \end{array} $$

Because the remainder $ \left( \color{red}{ -30 } \right) $ is not zero, we conclude that the $ x+2 $ is not a factor of $ x^{3}-2x^{2}-23x-60$.

First we need to create a synthetic division table.

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.

$$ \begin{array}{c|rrrr}\color{blue}{-2}&1&-2&-23&-60\\& & & & \\ \hline &&&& \end{array} $$

Step 1 : Bring down the leading coefficient to the bottom row.

$$ \begin{array}{c|rrrr}-2&\color{orangered}{ 1 }&-2&-23&-60\\& & & & \\ \hline &\color{orangered}{1}&&& \end{array} $$

Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -2 } \cdot \color{blue}{ 1 } = \color{blue}{ -2 } $.

$$ \begin{array}{c|rrrr}\color{blue}{-2}&1&-2&-23&-60\\& & \color{blue}{-2} & & \\ \hline &\color{blue}{1}&&& \end{array} $$

Step 3 : Add down last column: $ \color{orangered}{ -2 } + \color{orangered}{ \left( -2 \right) } = \color{orangered}{ -4 } $

$$ \begin{array}{c|rrrr}-2&1&\color{orangered}{ -2 }&-23&-60\\& & \color{orangered}{-2} & & \\ \hline &1&\color{orangered}{-4}&& \end{array} $$

Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -2 } \cdot \color{blue}{ \left( -4 \right) } = \color{blue}{ 8 } $.

$$ \begin{array}{c|rrrr}\color{blue}{-2}&1&-2&-23&-60\\& & -2& \color{blue}{8} & \\ \hline &1&\color{blue}{-4}&& \end{array} $$

Step 5 : Add down last column: $ \color{orangered}{ -23 } + \color{orangered}{ 8 } = \color{orangered}{ -15 } $

$$ \begin{array}{c|rrrr}-2&1&-2&\color{orangered}{ -23 }&-60\\& & -2& \color{orangered}{8} & \\ \hline &1&-4&\color{orangered}{-15}& \end{array} $$

Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -2 } \cdot \color{blue}{ \left( -15 \right) } = \color{blue}{ 30 } $.

$$ \begin{array}{c|rrrr}\color{blue}{-2}&1&-2&-23&-60\\& & -2& 8& \color{blue}{30} \\ \hline &1&-4&\color{blue}{-15}& \end{array} $$

Step 7 : Add down last column: $ \color{orangered}{ -60 } + \color{orangered}{ 30 } = \color{orangered}{ -30 } $

$$ \begin{array}{c|rrrr}-2&1&-2&-23&\color{orangered}{ -60 }\\& & -2& 8& \color{orangered}{30} \\ \hline &\color{blue}{1}&\color{blue}{-4}&\color{blue}{-15}&\color{orangered}{-30} \end{array} $$

Remainder is the last entry in the bottom row $ \left(\color{red}{ -30 }\right)$.

Synthetic Division Calculator