9.4k views
2 votes
What numbers add up to 2 and multiply to get -15?

1 Answer

2 votes
Set up 2 equations
A) x + y = 2
B) x * y =-15
We can change equation B into x = -15/y and substitute this into equation A

-15/y + y = 2

-15 + y^2 = 2y

y^2 -2y -15 =0
Factoring
(y +3) * (y-5) = 0

y = -3 and y =5
Then solve for x

User Vercas
by
6.4k points