I have attached the circuit of interest. The question is to find Vd (drop across diode as shown in the attached image). Sorry about the handwriting on there (those can be ignored). The answer was given to be Vd=-5V. I can't figure out how they got that answer. I don't feel there is enough information given to be bale to determine the drop. The voltage @ the left node of diode=+5V. You don't know the voltage @ the right node of the diode though. The voltage @ right node should be 10V-1KΩ*(I4). If the answer is -5V, then I4 must be 0, but I don't see how you could have solved for I4 with the amount of info that was given.