Kirchhoff's rules for resistors in parallel

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coleman221
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Homework Statement



Circuit schematic with a switch, a battery marked + and -, and resistors R1, R2 and R3; currents I1, I2 and I3 are labelled, with R1 and R2 in series and R3 connected across them.


Use Kirchoff's rules to determine I1, I2 and I3 for the following circuit:
Use the following values:ε = emf = 9 V
r = internal resistance = 1.5
R1 = 5
R2 = 15
R3 = 13.75

Homework Equations



The Attempt at a Solution


I found I1 to be .9328 by adding all the resistors together (taking into account that r3 was in parallel to r1 and r2) and adding the resistance of the battery.

I've been trying to use 0=ε-I1r-IR1-IR2
0=ε-I1r-I3R3
I1=I2+I3
I've done similar problems but this is for a lab instead of homework so its written in different a way (and they like to throw in things we haven't learned yet in lecture) so i think I'm having trouble visualizing where the currents are splitting and what parts are equivalent.
 
Why not redraw the circuit in a more conventional way, using the standard schematic symbols? It might help you to see ways to go about analyzing it.