Question 14
If $x$ is a 3-digit number, we define $M(x)$ and $m(x)$ respectively as the largest and smallest positive number that can be formed by rearranging the three digits of $x$. For example, if $x=123$, then $M(123)=321$ and $m(123)=123$. If $y=898$, then $M(898)=988$ and $m(898)=889$.
Given that $z$ is a 3-digit number that satisfies $z=M(z)-m(z)$, what is the value of $z$?
Given that $z$ is a 3-digit number that satisfies $z=M(z)-m(z)$, what is the value of $z$?