Dejo el codigo:
Código PHP:
$array1 = array(
array("fanpage" => "argentina", "likes" => "6824", "pedido" => "1000"),
array("fanpage" => "ecuador", "likes" => "5000", "pedido" => "1000"));
$union = array_merge($array1);
$resultado = array_values(array_map("unserialize", array_unique(array_map("serialize", $union))));
foreach ($resultado as $indice => $r)
{
foreach($r as $key)
{
$total=$r['likes']+$r['pedido'];
echo "<br>".$total;
}
}