#!/usr/bin/perl 
use strict; 
my $result; 
my $b; 
my $a; 
$result=&add_and_duplicte(2,3); 
print "2*(2+3) is $result\n"; 

$b=5;$a=10; 
$result=&add_and_duplicte($a,$b); 
print "2*($a+$b) is $result\n"; 

# add two numbers and mulitpy with 2: 
sub add_and_duplicte(){ 
    my $locala=shift; 
    my $localb=shift; 
    ($localb+$locala)*2; 
}