30 This is a tough one. You will need to use many of the ideas that A V 6 B have been discussed so far. Work 14 Q the Practice Problems first, then tackle this. Write 3 NVA equations at nodes I=1.7111 A V6, A, and B to find R. HINT: treat the current through R as an 6 V R unknown. Name it Ip. It is your third unknown