Answer:
I think the question is mistyping or wrong
Explanation:
A+B=16
A*B = -80
Convert to
A=16-B
Substitute
(16-B)*B=-80
16B-B^2+80=0
Change the sign to make it easier (multiply by negative number)
B^2 -16B-80
=(B - 4)(B + 20)
B1=-4 and B2=20
Then its match if the product is -80.
Or second option is, assuming that the sum is 18, not 16
The A would be 8 and the B would be 10