# How do i solve this circuit with Thevenin's? I am not sure how to place my voltage source after i combine the 2 parallel resistors R1 and R2. Can someone please help me with this?

Method1 (specific method for voltage divider):
After you simplified the parralel resistors $R_{23} = R_2 || R_3$ you got a voltage source with voltage divider formed by $R_{23}$ and $R_1$.

The Thevenin Equivalent of a voltage source $V_{src}$ with voltage divider is a Thevenin source with $V_{th}=V_{src}\frac{R_{23}}{R_1+R_{23}}$ and $R_{th}= R_1 || R_{23}$

Method2 (general method that works always):
If you don't know this shortcut above: do what you should have learned in the lessons:

• find open circuit voltage $V_{oc}$ between a and b
• find short circuit current $I_{sc}$ between a and b
• use both results to derive $V_{th}=V_{oc}$ and $R_{th}=\frac{V_{oc}}{I_{sc}}$.

First, r2//r3 so you find the equivalent resistance Req1. Then you see that R1 and Req1 are in series so you find the equivalent resistance between r1 an Req1 and i think it's good. you have your equivalent schema.

• The OP asked about using Thevenin. – Chu May 17 '17 at 14:18
• i should have said it was the beginning of method to find equivalent schema. After you just had to as @curd said. Sorry i wasn't explicit. – Dipo May 17 '17 at 14:39