Evaluate the limit $\lim_{x\to{- \infty }}\left(6x^5\right)$ by replacing all occurrences of $x$ by $- \infty $

Simplify $\left(- \infty \right)^5$ by taking the minus sign ($-$) out of the power

Infinity to the power of any positive number is equal to infinity, so $\infty ^5=\infty$

Any expression multiplied by infinity tends to infinity, in other words: $\infty\cdot(\pm n)=\pm\infty$, if $n\neq0$