#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my %data1 = (
    'NAME' => 'JOE DOE',
    'DATE' => '2015-05-05',
    'NUMBER' => '00001'
);

my %data2 = (
    'ACCOUNT1' => '1b',
    'ACCOUNT2' => '2b',
    'ACCOUNT3' => '3b',
    'ACCOUNT4' => '3d'
    );

=solution1
my %newHash = (%data1, %data2);

print Dumper \%newHash;
=cut

=solution2
@data1{keys %data2} = values %data2;

print Dumper \%data1;
=cut

__DATA__

$VAR1 = {
          'ACCOUNT4' => '3d',
          'ACCOUNT3' => '3b',
          'ACCOUNT2' => '2b',
          'ACCOUNT1' => '1b',
          'NUMBER' => '00001',
          'DATE' => '2015-05-05',
          'NAME' => 'JOE DOE'
        };