# Evaluate this alpha substitution in \$[(zx)/x]Î»z.xyz\$

I am having difficulty with the following problem :
Evaluate the following where the notation $$[y/x]$$ means replace $$x$$ with $$y$$:

$$[(zx)/x]Î»z.xyz$$

Attempt:
If I were to simply replace $$x$$ with $$zx$$ in this expression it would yield :
$$lambda z.zxyz$$ but I am not sure if this is correct. Any tips appreciated.