- #1

Duc Anh Le

- 3

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**This i a test question and we are not allowed to use a calculator, so I was wondering whether I did everything correctly, since the I1 = - 1/7. I am supposed to find out I3, but stopped at I1, since the result is a bit tricky.**

1. Homework Statement

1. Homework Statement

R1 = 10 ohm, R2 = 20 ohm, R3 = 40 ohm

I3 = ?

## Homework Equations

I3 = I2 + I1

V1 = I1 * R1 + I3 * R3

V2 = R2 * I2 + I3 * R3

## The Attempt at a Solution

10 = 20I1 + 40 I2 + 40I1

20 = 20I2 + 40I1 + 40I2

-10 = 70I1

I1 = -1/7