The context of the following conversation is After looking it over on the black board, Lee solved Taylor's equation.:
Lee says Do you know about that equation Taylor has been having trouble with?.
The friend responds The one on the blackboard?.
Lee responds Yeah, that one, I think I solved it..
The friend responds Wow, that's a difficult equation..
Lee responds I hope Taylor isn't mad..
The friend responds You can keep it a secret from Taylor and give hints about how to solve it..