Use the return value of method x() for the conditional in an if statement like you did in the body of the x() method. If x() returns true print one thing, else print something else.
It sure seems like this boolean method is unnecessary.
For example instead of the entire body of the x() method you could use the following line:
return y() >= z;
because the statement:
y() >= z
will evaluate to a boolean value and you can simply return it rather than saying if(true) { return true; } else { return false; }
That being the case you could replace the call to x() in the code with y() >= z and forget the method x() completely.
Anyway too many possibilities, and I am rambling at the wee hours of my morning. Someone will be happy to look over what you have if you want to post it.