Find the current in each part of the circuit.

Explanation

To find the current in each part of the circuit, we will apply Kirchhoff's laws. Let's break down the solution step by step.

### Step 1: Identify the Circuit Components
We have a circuit with two resistors and two currents, \( I_1 \) and \( I_2 \). The voltage source is 4.5 V and we have resistances of 3 ohms and 6 ohms.

### Step 2: Apply Kirchhoff's Voltage Law (KVL) to the First Loop
Starting from the voltage source (4.5 V) and moving through the resistors, we can write the equation for the first loop:
\[
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