How Do You Calculate Resistance in Complex Circuits?

[Maigowai]

Homework Statement

What is the value of resistance R in the figure, if the current through the battery is 5.0A?

Homework Equations

V=IR
Rt = (1/R1 + 1/R2)^-1 + R3

The Attempt at a Solution

Rt = V/I
Rt = 2V/5A
Rt = 0.4ohms

0.4 = (1/0.5 + 1/R)^-1 + 0.1
R = -5 ohms

(the answer given is 0.750 ohms)

 

[skeptic2]

Everything looks correct down to and including 0.4 = (1/0.5 + 1/R)^-1 + 0.1

I started from that point and got the correct answer. Check your arithmetic again.

 

[Maigowai]

Everything looks correct down to and including 0.4 = (1/0.5 + 1/R)^-1 + 0.1

I started from that point and got the correct answer. Check your arithmetic again.

oh yeah haha you're right, I messed up in my algebra, thanks!

 

[Maigowai]

Everything looks correct down to and including 0.4 = (1/0.5 + 1/R)^-1 + 0.1

I started from that point and got the correct answer. Check your arithmetic again.

if you could, please take a look at my other quetsion here: https://www.physicsforums.com/showthread.php?p=3478610#post3478610