SOLUTION: What multiplies to -90 and adds to -4?

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Question 1044027: What multiplies to -90 and adds to -4?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
xy=-90
x+y=-4
y=-90/x
x+(-90/x)=-4
multiply all by x
x^2-90=-4x
x^2+4x-90=0
x=(1/2)(-4+/- sqrt(16+360));sqrt 376=19.39
x=(1/2)(-4-19.39) or -11.7; y=(1/2)(-4+19.39)=7.7
The exact value is -2+(1/2)sqrt(376) and -2-(1/2) sqrt (376). That product is 4-(1/4)(376)=-90
and the sum is -4.