Question

Factor over Complex numbers?

Answer 1

I missed this class, thought I had the concept, and ended up not doing so well on the test. Could someone help me answer these study guide questions and show me how?

1. X^2+7

2. X^2+25

3. X^4-81

Answer 2

How would you factor x^2 - 7?

Answer 3

I thinkkkkkk I figured it out. These were the answers I got, are they right?
(x-isqrt7)(x+isqrt7)
(x-5i)(x+5i)
(x-3)(x+3)(x-3i)(x+3i)

I found something in my textbook on the subject, but Im really unsure of myself lol

Answer 4

Perfect. No need to be unsure.