Given the expression:
![\displaystyle \large{ \sqrt[3]{ - 125} }](https://img.qammunity.org/2022/formulas/mathematics/high-school/1oz27qb1h98k3qunqetxe2u0ygg4edz2mi.png)
Definition:
![\displaystyle \large{ y = \begin{cases} \pm \sqrt[n]{x} \longrightarrow n = (2,4,6,8,...) \: \: (x \geqslant 0) \\ \sqrt[n]{x}\longrightarrow n = (1,3,5,7,...) \: \: (x \in \R) \end{cases}}](https://img.qammunity.org/2022/formulas/mathematics/high-school/i7mc40d8zwx91zohz9ld5noxrcgsih64bx.png)
First, factor the -125. -125 comes from (-5)×(-5)×(-5) or (-5)^3.
![\displaystyle \large{ \sqrt[3]{ ( - 5) * ( - 5) * ( - 5)} }](https://img.qammunity.org/2022/formulas/mathematics/high-school/14hmglorqpv7h1fmbgp2xi6l6eli0j9go4.png)
Because if (-5)^2 = 25 then 25×(-5) again will be -125.
Since this is the cube root, we have to pull out 3 terms in one. There are 3 fives that we can take off and therefore,
![\displaystyle \large \boxed{ - 5}](https://img.qammunity.org/2022/formulas/mathematics/high-school/mp1xdpwxsx4beiy21k3syfqfn5lzjylctt.png)