Java:

class Expr1 {
    public static int twice(int x) {
	return x*2;
    }
}

Bytecode:

javac -g Expr1.java
javap -c -l Expr1

public static int twice(int);
  Code:
   0:   iload_0    // load int from var 0 to top of stack
   1:   iconst_2   // push 2 on top of stack
   2:   imul       // replace two topmost elements with their product
   3:   ireturn    // return top of stack
}

class Expr2 {
    public static int cubeArea(int a, int b, int c) {
	return (a*b + b*c + a*c) * 2;
    }
}

Bytecode:

javac -g Expr2.java
javap -c -l Expr2

public static int cubeArea(int, int, int);
  Code:
   0:   iload_0
   1:   iload_1
   2:   imul
   3:   iload_1
   4:   iload_2
   5:   imul
   6:   iadd
   7:   iload_0
   8:   iload_2
   9:   imul
   10:  iadd
   11:  iconst_2
   12:  imul
   13:  ireturn
}
  LocalVariableTable: 
   Start  Length  Slot  Name   Signature
   0      14      0    a       I
   0      14      1    b       I
   0      14      2    c       I