What are the odds here?
Pittsburgh 39o -110
Denver 3.5 -110

thats +3.5 not -3.5

-3.5: PIT favored by 3 1/2 points

39o: is the over/under line...do you think both teams together will score over 39 or under 39

-110 simply means you must bet $110 to win $100

Tough to tell the way it is written. I would venture to guess that the over under is 39, with the regular juice, meaning you bet 1.10 to win a buck. Denver is getting three and a half with the same odds, 1.10 to win a buck.

Pitt -3.5
Pitt/Den over/under 39

Take Pitt and give the 3.5 and forget the total.