SOLUTION:
Algebra.Com
Question 392001:
Found 2 solutions by Alan3354, richard1234:
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
Col Mustard with the candlestick.
Answer by richard1234(7193) (Show Source): You can put this solution on YOUR website!
Yes, we are proving the existence of an empty set.