2.20 An ideal op amp with 5- kΩ and 10- kΩ resistors is used to create a +2.5-V supply from a −5-V reference. Sketch the circuit. What are the voltages at the ends of the 5- kΩ resistor? If these resistors are so-called 1% resistors, whose actual values are the range bounded by the nominal value ±1%, what are the limits of the output voltage produced? If the −5-V supply can also vary by ±1%, what is the range of the output voltages that might be found?