Answer:
i believe the answer is the 4th one. sorry, i cant figure out how to write it on computer...
75
3 x 25
3 x 5 x 5
3-/5 (i tried)
1. if there are an even number of the same number on the right side of the square root, then it just becomes one and stays on the right.
2. if theres just one of that number on the right side, then it goes on the left, because there isnt anything to match it.
3. if there is an odd number of the same number on the right side, then one goes on the left, and the rest follow the even rule (#1)
idk if that made sense, but its how my mind works. if you need a clear version, then dont be afraid to ask. ill try to clear it as simply as i can. :P