can someone please explain to me how they are getting these numbers? I understand that if the resistance changes and the voltage is constant it changes the current/amps and that in turn will change the voltage. so my understanding from these diagrams is that if you have 9v and 3ohms you'll have 3amps and V=IxR which would give you either 30v or 39v between resistor 1 and 2 depending on if you're suppose to add the resistance of the first two resistors or not which is specified. but I don't understand how they are getting 1.5v, 5v, and 2.5v and how the fuck is E2 two different values?