num_gen.php

<?php

$numbers = array(
    mt_rand(1, 200),
    mt_rand(1, 200)
); 

echo $json_encode($numbers);
 
?>

the_js.js

function drawGauge() {
  // THIS IS WHERE WE CALL THE PHP AND GET THE NUMBERS AND TURN THEM INTO JS VARIABLES.
  $.getJSON('num_gen.php', function(numbers) {
     var num1 = numbers.1;
     var num2 = numbers.2;
  }
  gaugeData = new google.visualization.DataTable();
  gaugeData.addColumn('number', 'CPU');
  gaugeData.addColumn('number', 'RAM');
  gaugeData.addRows(2);
  gaugeData.setCell(0, 0, num1);
  gaugeData.setCell(0, 1, num2);
 
  gauge = new google.visualization.Gauge(document.getElementById('gauge_div'));
  gauge.draw(gaugeData, gaugeOptions);
}