For any number $x$, we are told that $x\&=7-x$ and $\&x = x -7$. What is the value of $\&(12\&)$?

For any number $x$, we are told that $x\&=7-x$ and $\&x = x -7$. What is the value of $\&(12\&)$?

 

Pls include steps not just answer

Thanks!