I am using multisim to simulate an inverting summing op amp (LM741CN). I calculate my expected Vout to be the following: -Vout = ((20/2.5)V1) + ((20/5)V2) + ((20/10)V3) + ((20/20)V4). According to my calculations, my Vout with binary input of 0001 should be -1. However, when I measure in Multisim, that is not what I get. Are my calculations incorrect or am I measuring incorrectly?