Hello..i have problems connecting my LG led TV to my LG ARX8500 sound system ,so therefore i can't get to hear my TVs audio.

Without the TV model number I can't be sure but you should have an digital optical audio output on the TV,. You do have an optical input on the HTS.
You may have to turn the optical out on, the TV speakers off, and change the audio output type in the TV audio menu.