conversations.from: human
conversations.value: I would love to understand how to solve this problem: If Sam and Harry have 100 feet of fence between them, and they agree to split it with Harry getting 60 feet more than Sam, how much is left over for Sam?
  Can you explain?
conversations.from: assistant
conversations.value: Let x be the amount of fence Sam gets and y be the amount Harry gets. We know that y = x + 60, and y + x = 100.
  Substituting the first equation into the second equation, we get 2x+60=100
  Subtracting the 60 from both sides, we get 2x=40
  We divide each side by two, leaving x=20. This means Sam has 20 feet of fence left over.