How to mount an ISO file in ubuntu?

Maybe, instead of installing additional software, you can use what the system has to this end:

1. Create a directory to serve as the mount location:

   sudo mkdir /media/iso
   

2. Mount the ISO in the target directory:

   sudo mount -o loop path/to/iso/file/YOUR_ISO_FILE.ISO /media/iso
   

3. Unmount the ISO:

   sudo umount /media/iso
   

On your desktop will appear the mounted ISO.

How to Install PHP 5.6 or PHP 7.1 on Ubuntu 16.04, 14.04 or 12.04 using PPA

https://tecadmin.net/install-php5-on-ubuntu/#