Multiply (3-2i)²=3²-2(3)(2i)+(2i)²

gr.11 student...Angie

You are correct so far. 3² = 9 and 2(3)(2) = 12 so

But (2i)² = (2i)(2i) = (2)(2)(i)(i) = 4 i² and i² = -1. Thus

(3-2i)² 9 + 12 i + (2i)² = 9 + 12 i - 4 = 5 + 12 i