What you are looking for is more like this:
public class Exercise {
private static int x = 12;
private static int y = 28;
private static double z = 3.3;
public static void main(String[] args) {
double result = calculate();
System.out.println("The answer to (x * y) / z is " + result);
}
private static double calculate() {
double you = (x * y) / z;
System.out.println("you = " + you);
return you;
}
}
As others said, a return must be the last instruction of the method (unless enclosed in a conditional).
You have also to be careful: printing "you" is not the same as printing you the variable.