How is $x and $y global variables if they don't have global written before them?
<!DOCTYPE html>
<html>
<body>
<?php 
$x = 75;
$y = 25; 
function addition() {
     $GLOBALS['z'] = $GLOBALS['x'] + $GLOBALS['y'];
}
addition();
echo $z;
?>
</body>
</html>
 
    