Does the resistor values used for opamp circuits come from the equations?
An ideal operational amplifier has infinite input impedance, zero parasitic leakage current and offsets, and zero output impedance. Therefore in this case ANY resistors are good, mathematically.

Real amplifiers do have finite output impedance (~30 Ohms and up to 1k), and noticeable input impedance (down to 300k for old designs like LM741). To get approximate functionality of OA to the best degree possible, the resistors must be much bigger than output impedance, but much smaller than input impedance. This gives you some choice to make. Sometimes the choice is narrow, like in your homework case, between 10k and 100k.