Question

Design an operational amplifier circuit with an output voltage of the form v=k(v1-v2-v3) where v1, v2 and v3 are the input voltages into the input terminals 1,2 and 3 respectively.

Answer 1

design a subtractor circuit....
In -ve part pass v2+v3.... note an suming circuit is required at input.... (OPAMP summing amplifier)
In +ve n pass v1....
set gain resistances such that gain is k