1)(x<sub>1</sub> + i • y<sub>1</sub>) + (x<sub>2</sub> + i • y<sub>2</sub>) = (x<sub>1</sub> + x<sub>2</sub>) + i • (y<sub>1</sub> + y<sub>2</sub>) | 1)(x<sub>1</sub> + i • y<sub>1</sub>) + (x<sub>2</sub> + i • y<sub>2</sub>) = (x<sub>1</sub> + x<sub>2</sub>) + i • (y<sub>1</sub> + y<sub>2</sub>) |