Here is the other question i was gonna mention, Ace =.= i would put it in the comments but i dont want to deal with brainly being annoying and such again

Answer:
a.) 9, -9
b.) 2(sqrt)15, -2(sqrt)15
c.) 4, -2+2i(sqrt)3, -2-2i(sqrt)3
d.) 3(sqrt)75
(some of the numbers are placed differently than I wrote them so here are screenshots- pls look at them rather than what I wrote ;w;)