if you apply for several credit in the same day its consider to be one inquire?
Also the delta sky miles my score is 514 im sure im not going to get approved?
Well, unfortunately your score is indeed a bit too low for Amex. I've seen people get approved for the Gold Delta Skymiles and Green cards with scores around 620 though, so if you can get some GWs to work for you there is still hope.
And yes, Amex will use the same inquiry for multiple applications in the same day.