Apache2 does not interpret PHP

I usually installed PHP and APACHE2 but it does not interpret the PHP code, follow test code:

<?php echo "teste"; 

It returns me an "html" page with this typed, and comes from a "print" written test

Files not found in the / var / www / html folder with 755 permissions I did not change anything in the apache2 settings I just gave start

I read about changing the httpd.conf file but I do not find it inside my system