I don't recognize the round leaf one, but I see some dandelion mixed in there.
Where are you? This might be a clue to IDing the round leaved one.
I have them all over my yard. They only seem to flower for a short period of time in the spring/early summer.I was going to say violet too, but the ones I have had that looked like that and I thought were violets, never got any flowers, so I wasn't sure if that's what it was.