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## Homework Statement

An image of the circuit:

http://gyazo.com/32ec8c06fb861d115895bec5a15959dd

## Homework Equations

##P = ±IV##

## The Attempt at a Solution

So the first thing i want to do is solve for all the powers that are absorbed or supplied.

##P_{10V} = (2A)(10V) = 20W##

##P_1 = ##

##P_2 = -(2A)(15W) = -30W##

##P_3 = (2A)(15V) = 30W##

##P_{10VI_x} = -(I_x)(10V) = -10WI_x##

##P_{25V5A} = -(5A)(25V) = -125W##

So by Tellegen's theorem:

##20W + P_1 - 30W +30W - 10WI_x - 125W = 0##

##P_1 - 105W = 10WI_x##

Solving that will give ##I_x##, but I have a problem. I'm not sure about how to find ##P_1##. I know 1A of current will be flowing through it ( my

**guess**is from positive to negative, though I can't justify this ) so that element 1 will absorb power.

The answer is listed as ##I_x = -2A##.

I'm confused here.

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