I can’t install original or newer OS.

Hello all,

I am seeking help as, Ideally, I would like to format my MacBook Pro 7,1 (mid 2010) and update the OS from 10.6.8 to El Capitan. I have started by trying to re-format to original factory settings by using the dvds which came with the laptop (please see photos) but when I try to boot from DVD by pressing C after turning the laptop on with the disk already in, I can hear the disk running but within a few seconds the disk gets ejected. The same happens if I try using the Snow Leopard OS install disk. This is why I tried to install directly El Capitan which I downloaded from the Apple support page but, as soon as I try to open it, a window appears saying that the OS is not supported. I therefore downloaded Yosemite which is fine as it lets me open it but after I select the disk where I want to install it, I press “install” and after the process ends nothing happens, I turn the computer off and on and also nothing happens.

would anyone be able to suggest what it is that I am doing wrong please?

thank you very much in advance.