I think the first one is a fold. The flop is so dry that he can definitely be slow playing set all the way down to the river. Definitely a backdoor flush is possible, as well as a raise from KJ. All of these hands seem reasonable here.

Second one I call, cause the 5 river takes away a lot of the combo's he's repping. I'd have a lot easier time folding if the river wasn't a 5.

(edit: though I do admit.. that turn bet just looks like its sucking us in. But 78 doesn't get there, and 34/46 could be turning into a bluff? meh...)