For any negative real number $x$, the value of $2x$ will be less than the value of $\frac{1}{2}x$. Therefore, $\frac{1}{2}x$ cannot be the least of the five values. Thus, the least of the five values is either $x-2$ or $2x$. When $x < -2$, we know that $2x - (x-2) = x + 2 < 0$. Since the difference between $2x$ and $x-2$ is negative, then $2x$ has the smaller value and so is the least of all five values.