我如何在PHP中划分两个语句

<?php
     $q2 = "SELECT SUM(crd)
           FROM coe_courses
           INNER JOIN student_record ON coe_courses.course_number = 
            student_record.course_number WHERE student_record.id =".$_SESSION['user_id'] ;
     $result = mysqli_query($con , $q2 ) ;
     if($row = mysqli_fetch_array($result)){
         echo $row["SUM(crd)"];
     }
     $q2a = "SELECT SUM(points) FROM student_record where student_record.id =".$_SESSION['user_id'] ;
     $result = mysqli_query($con , $q2a ) ;
     if($row = mysqli_fetch_array($result)){
       echo $row["SUM(points)"];
     }
?>

我编写了这段代码，但是如何在代码末尾对这些语句进行划分

echo $row["SUM(crd)"] /$row["SUM(points)"];