Determine load bearing wall
I’d check: 1) roof framing, 2) top plate, 3) sole plate fasters, 4) wall sheathing

1) If the roof framing is identical over the “no wall” area as the “wall to be removed” area, then I’d assume it is not a load bearing wall. 

2) If there’s a single top plate at the wall to be removed, then that would give additional indication that it’s not load bearing. 

3) If there are no bolts with over sized washers (3” sq. Washers) in the wall to be removed, then that is an indication that it’s not a load bearing. 

4) If there’s no wall sheathing (plywood, OSB board, etc.) then it’s not a lateral resistance wall. 

If all indications are “negative”, then I’d assume it’s okay to remove. 

Note: I did not mention checking for a footing, because you indicated your house is slab-on-grade.