Electronics. How to find the average of two signals?

Question

Electronics

Hello!
Tell me a variant of an analog circuit that allows you to get a signal at the output, which is the average of two signals applied to the input.

Answer 1

adder on op amp

Answer 2

if the output resistance of the signal sources is zero, and the input resistance of the meter is infinite, then two resistors of the same rating will be enough - connect each output with a resistor to the input and the input will have half the sum of the input potentials.