Lin says, "When you add or multiply two complex numbers, you will always get an answer you can write in a + bi form."
Noah says, “I don't think so. Here are some exceptions I found:"
(7 + 2i) + (3 - 2i) = 10
(2 + 21) (2 + 2i) = 8i
a.
Check Noah's arithmetic. Is it correct?
b.
Can Noah's answers be written in the form a + bi, where a and b are real numbers? Explain
or show your reasoning.