I think first hand is a pretty standard call - you're getting 15.5-1 on your money, so you only have to be right a small percentage of the time to be profitable. The last two hands I'm not so sure about. The 2nd hand looks a lot like a made straight, two pair, or small set - against that range you may have 6 outs. I probably fold the river unimproved without more of a read than "moderately aggresive". The third hand is more read-dependent than anything else. If this player will defend with any two and will raise with overcards - then it's an easy call down. If they're more selective, well, I guess hope they hit a 7 or raised the turn with a flush draw or j-9, because this is hard not to call, even though a better two pair is very possible with this board