Find remainder when $ -x^{3}+24x-5 $ is divided by $ x+5 $.

The synthetic division table is:

$$ \begin{array}{c|rrrr}-5&-1&0&24&-5\\& & 5& -25& \color{black}{5} \\ \hline &\color{blue}{-1}&\color{blue}{5}&\color{blue}{-1}&\color{orangered}{0} \end{array} $$

The remainder when $ -x^{3}+24x-5 $ is divided by $ x+5 $ is $ \, \color{red}{ 0 } $.

We can find remainder using synthetic division method.

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.

$$ \begin{array}{c|rrrr}\color{blue}{-5}&-1&0&24&-5\\& & & & \\ \hline &&&& \end{array} $$

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

$$ \begin{array}{c|rrrr}-5&\color{orangered}{ -1 }&0&24&-5\\& & & & \\ \hline &\color{orangered}{-1}&&& \end{array} $$

Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -5 } \cdot \color{blue}{ \left( -1 \right) } = \color{blue}{ 5 } $.

$$ \begin{array}{c|rrrr}\color{blue}{-5}&-1&0&24&-5\\& & \color{blue}{5} & & \\ \hline &\color{blue}{-1}&&& \end{array} $$

Step 3 : Add down last column: $ \color{orangered}{ 0 } + \color{orangered}{ 5 } = \color{orangered}{ 5 } $

$$ \begin{array}{c|rrrr}-5&-1&\color{orangered}{ 0 }&24&-5\\& & \color{orangered}{5} & & \\ \hline &-1&\color{orangered}{5}&& \end{array} $$

Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -5 } \cdot \color{blue}{ 5 } = \color{blue}{ -25 } $.

$$ \begin{array}{c|rrrr}\color{blue}{-5}&-1&0&24&-5\\& & 5& \color{blue}{-25} & \\ \hline &-1&\color{blue}{5}&& \end{array} $$

Step 5 : Add down last column: $ \color{orangered}{ 24 } + \color{orangered}{ \left( -25 \right) } = \color{orangered}{ -1 } $

$$ \begin{array}{c|rrrr}-5&-1&0&\color{orangered}{ 24 }&-5\\& & 5& \color{orangered}{-25} & \\ \hline &-1&5&\color{orangered}{-1}& \end{array} $$

Step 6 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ -5 } \cdot \color{blue}{ \left( -1 \right) } = \color{blue}{ 5 } $.

$$ \begin{array}{c|rrrr}\color{blue}{-5}&-1&0&24&-5\\& & 5& -25& \color{blue}{5} \\ \hline &-1&5&\color{blue}{-1}& \end{array} $$

Step 7 : Add down last column: $ \color{orangered}{ -5 } + \color{orangered}{ 5 } = \color{orangered}{ 0 } $

$$ \begin{array}{c|rrrr}-5&-1&0&24&\color{orangered}{ -5 }\\& & 5& -25& \color{orangered}{5} \\ \hline &\color{blue}{-1}&\color{blue}{5}&\color{blue}{-1}&\color{orangered}{0} \end{array} $$

Remainder is the last entry in the bottom row $ \left(\color{red}{ 0 }\right) $.

Synthetic Division Calculator