How Can I Play this Different??

How Can I Play this Different??

Over the last week I have lost two big pots over playing the same hand in similar situations. Any opinions on how to play it differently???

I have ace king in the big blind in both situations. I cant remember exactly what happened earlier in the week but this is what happened when I lost a pot monday.
I have ace king in the big blind. There are two flat callers and the small blind, playing 1 / 2$ cash table Im sat with about 280$. I raise it to 8$ and both the limpers call and the small blind passes.

Flop is ace 9 4. I see this as a good flop, so I decide to check and try to trap a little and bet on the turn heavy. Do you think thats a mistake?

So I check and the first guy bets 10 dollars and the other guy passes.

Now should i raise there and see where I am? Instead I just flat call.

Turn card is a 6. The guy has 90 dollars left.

Probs I shot my load here I decide to check again and he bets 20 and i raise him all in. he calls and shows 444.....ooops!! anyone got any ideas on how to play it. I think ace king should be played so much differently in cash to a tourny.