conversations.from: human
conversations.value: Stacy has 32 berries. Steve takes 4 of Stacy's berries, and still has 7 less berries than Stacy started with. How many berries did Steve start with?
  Find the solution.
conversations.from: assistant
conversations.value: Let x be the number of berries Steve started with
  x+4=32-7
  x+4=25
  x=21 berries