$x = true;
$tries = 0;
while($x):

    $numbers = array(1,2,3,4,5,6,7,8,9);
    shuffle($numbers);
    $matriz = array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i');

    $num = 0;
    foreach($matriz as $key => $value):
        $new_matriz[$value] = $numbers[$num];
        $$value = $numbers[$num];
        $num = $num + 1;
    endforeach;

    if( $a + $b + $c == 15 &&
        $d + $e + $f == 15 &&
        $g + $h + $i == 15 &&
        $a + $d + $g == 15 &&
        $b + $e + $h == 15 &&
        $c + $f + $i == 15 &&
        $a + $e + $i == 15 &&
        $g + $e + $c == 15 ){

        echo "<br>".$a . $b . $c ."<br>";
        echo $d . $e . $f ."<br>";
        echo $g . $h . $i ."<br><br>";
        echo 'Tentantivas: '.$tries."<br>";
        $x = false;
    }else{
        $tries = $tries + 1 ;
        $x = true;
    }
endwhile;