Rear engine rider deck issue

I have noticed when cutting the deck does not appear to be level.
Tried adjusting it but can not seem to get it right. Couple of questions.
1) how much different should the height be front to back?
2) how do you adjust the height on the front of the deck seems to be off
at least 1/2" or more.
Thanks,
Doug

First things first. Check air pressure in tires. They must be the same on each axle at least. Second front should be 1/4 to 1/2 inch lower than back. I do not know how to adjust the decks on snapper RER..