Evaluating Methods: Lab 7b

Identify the output produced by the segments of code below or indicate if an error occurs. 
  1.           public static void main(String[] args ){
            int x = 2, y = 3, z = 0;
            z = p(x,y);
            System.out.print( "x = " +  x +  "y = " +  y + "z = " +  z);
          }

          public static int p (int a, int b ){
            int x = 21;
            a = 31;
            b = 41
            return b - a;
          }
        
  2.           public static void main(String[] args ){
            int x = 2, y = 3;
            x = p(x,y);
            x = p(x,y);
            x = p(x,y);
            System.out.print( "x = " +  x +  "y = " +  y);
          }
          
          public static int p (int y, int x){
            return 2*x + y;
          }
        
  3.           public static void main(String[] args ){
            int x = 2, y = 3, z = 0;
            x = p(x,y);
            System.out.print( "x = " +  x +  "y = " +  y + "z = " +  z);
            x = p(x,y);
            System.out.print( "x = " +  x +  "y = " +  y + "z = " +  z);
          }

          public static int p (int x, int z ){
            int y = z;
            return x - z;
          }
        
  4.           public static void main(String[] args ){
            int x = 2, y = 3, z = 0;
            display (x, z);
            System.out.print("INSIDE MAIN");
            System.out.print( "x = " +  x +  "y = " +  y + "z = " +  z);
          }

          public static void display (int x, int y){
            int z = x;
            System.out.print("INSIDE DISPLAY");
            System.out.print( "x = " +  x +  "y = " +  y + "z = " +  z);
          }
    Why is there no return statement in the Display method? Why is the call to display() not part of an assignment statement? 
  5.           public static void main(String[] args ){
            int x = 2, y = 3, z = 0;
            display (x, y, z);
          }

          public static void display (int a, int b, int c ){
            System.out.println( "a = " +  a +  "b = " +  b + "c = " +  c);
          }
        
  6.           public static void main(String[] args ){
            int x = 2, y = 3, z = 0;
            display (x, y, z);
            System.out.println("INSIDE MAIN");
            System.out.println( "x = " +  x +  "y = " +  y + "z = " +  z);
          }

          public static void display (int y, int z, int x ){
            System.out.println("INSIDE DISPLAY");
            System.out.println( "x = " +  x +  "y = " +  y + "z = " +  z);
          }