# How do you factor the expression x^3+121x?

Jan 9, 2016

You find the common factor in all terms.

#### Explanation:

We can rewrite the expression as products:

$\textcolor{red}{x} \cdot x \cdot x + 121 \cdot \textcolor{red}{x}$

We can see that both terms are mutiplying $x$, so:

$x \left(x \cdot x + 121\right) = x \left({x}^{2} + 121\right)$

Also, if you wish to simplify the number, in this case you're fortunate for being able to do so, as ${11}^{2} = 121$:

${x}^{3} + 121 x = x \left({x}^{2} + {11}^{2}\right)$