1. The problem statement, all variables and given/known data Consider the following voltage divider circuit with these values: R1= 10.0 kΩ, R3= 15.0 kΩ, E1= 13.0 V. What is the percent change in Vx when we connect a load resistor Rx = 10 R3? http://a.imageshack.us/img25/1546/circuity.th.png [Broken] 2. Relevant equations V1 = E * R3 / (R1 + R3) R3x = 1/R3 + 1/Rx = 1/REq V2 = E * R3x / (R3x + R1) Use division with the voltage solutions to find the percentage change. 3. The attempt at a solution I went ahead and found V1, which in this case was 7.8V Then I found R3x, which was 13.6 kohms After using R3x with the V2 equation it appears the percentage change is wrong. So I have to assume that 10*R3 isn't a simple multiplication of the resistance value, and that sounds right, except for the fact that I haven't taken a physics course for years and can't remember what you do differently when you multiply a resistance value. Okay, I apologize I should have posted my results first: V1: 13*0.6 = 7.8 R3x = 13.64 V2: 13*0.58 = 7.5 Percentage Change = 3.8 % (which is wrong) I'm not sure why its wrong exactly, but any help would be greatly appreciated.