Added Tutorial 9 code

Author: dima_los

README.md

@@ -20,4 +20,6 @@ I use PHP 8.2 and XAMPP here.
 - [Tutorial 3 - Write your first PHP program](https://www.youtube.com/watch?v=W2D190HCuu4)
 - [Tutorial 4 - Variables Part 1](https://www.youtube.com/watch?v=uOxKLq7-lxo)
 - [Tutorial 5 - How to mix PHP and HTML](https://www.youtube.com/watch?v=9Uu5kzJdpiQ)
-- [Tutorial 6 - Conditional statements - if/elseif/else](https://www.youtube.com/watch?v=9HMOnISd3FY)
+- [Tutorial 6 - Conditional statements - if/elseif/else](https://www.youtube.com/watch?v=9HMOnISd3FY)
+- [Tutorial 7 - Operators - Part 1](https://youtu.be/6W_99tS53nM)
+- [Tutorial 8 - Operators - Part 2](https://youtu.be/WI0nNAbIUE0)