Can you help me with one math SAT question?

Question

http://www.4tests.com/exams/questions.asp?qid=4186&nqid=4186&rev=1&dir=v&exid=9127383&qc=48

does that make sense

Answer 1

yeah it does. To do this set up two equations. x+y = -15 and xy=56. I used substitution method. I got x = -15-b. plugging that back in i get -15b - b^2 = 56. This equals b^2 + 15b + 56 = 0.