Question

What two numbers multiply to negative 8 but add to negative 7

Answer 1

Let "a" and "b" be the two numbers
So a*b=-8 and a+b=-7
Therefore S=-7 and P=-8
Using (x^2)-S+P=0 => (x^2)-(-7)+(-8)=0 => (x^2)+7-8=0
By factorizing we get (x+8)(x-1)=0
So a can be either -8 or 1 and b can be 1 or -8 
Meaning that the two numbers are -8 and 1.