I installed a couple of Ubuntu versions previously only to be deleted or unused leaving the allocated space they used haunted.Using a tool like GParted how can I merge all those pieces into my original HDD space which was 500GB.Below is the picture of how it looks.Help needed very badly.
First, delete all the old partitions that you don't want, using gparted. Then resize the remaining partition to take up that extra space. It's pretty point and click; just be sure and do it from a live CD.
Unneeded; kept for posterity
When you're done, the partition will indeed be bigger, but Ubuntu's ext4 filesystem won't know it. To fix this, do
sdaX with the proper name of your partition. Then reboot and you should be done!
To make room for ChromeOS, don't resize Ubuntu to take up all of the space; leave an unallocated block for ChromeOS. I'm not familiar with ChromeOS's install procedure, but it will probably offer to use the unallocated space.