Answer:
4FeS + 7O₂ ----> 2Fe₂O₃ + 4SO₂
Explanation:
You have to drag the elements shown on the right under the formula. For example, you would have to drag 4 of the FeS molecules under the 4FeS text in the formula. Then place 7 O₂ molecules under the 7O₂ text, etc.