Question

what numbers multiply to equal -9 but add up to 12?

Answer 1

I don't think this is possible.

The factors of -9 are:
-1 x 9
-9 x 1
-3 x 3

And when you add them together you get:
-1 + 9 = 8
-9 + 1 = -8
-3 + 3 = 0

Sorry but there is not an answer. :(