I'm supposed to find the Thevenin equivalent external to the resistor R in the image below. For Rth I got 2.5 ohm. Is that right?

And how do I find Eth?

 

Well I get Rth = 7.5Ω.
To find Vth remove load resistor (R) and find the voltage across open load terminal.

 

Well I get Rth = 7.5Ω.
To find Vth remove load resistor (R) and find the voltage across open load terminal.

Yeah, my Rth was 5 + 2.5, not 2.5, so I also get 7.5. But I don't quite understand how to find the voltage across an open terminal..

 

But I don't quite understand how to find the voltage across an open terminal..

Maybe this diagram will help

 

Maybe this diagram will help

Thanks, but it's still not clear to me. My guess from this is that Eth=10V. Is that right by any chance?

 

My guess from this is that Eth=10V. Is that right by any chance?

Bullseye Vth=10V

 

Bullseye Vth=10V

Cool. Maybe I did get it after all