1. The problem statement, all variables and given/known data A circuit is constructed with five resistors and a battery as shown. The battery voltage is V = 12 V. The values for the resistors are: R1 = 75 Ω, R2 = 127 Ω, R3 = 129 Ω, and R4 = 130 Ω. The value for RX is unknown, but it is known that I4, the current that flows through resistor R4, is zero. What is I1, the magnitude of the current that flows through the resistor R1? 2. Relevant equations V=IR 3. The attempt at a solution I've tried writing down everything I know. The strategy that I'm trying to take is to find Req, and Ieq, and then find the voltage across R1 to use the relevant equation to get the current. Rx, R2, and R4 are in parallel, so I2R2=I4R4=IxRx, and 1/R2 + 1/R4 + 1/Rx = 1/R(24x) After I added those resistors, it seemed that all the resistors (1, 3, 24x) would be in series, but I'm not sure. If this is true, R1 + R(24x) + R3 = Req Veq=Ieq(Req) Veq=V1+V24x+V3 And V1/R1=I1 I feel like I probably have too many equations, but I don't know how to put them all together.