SOLUTION: y = x^2 x^2 + y^2 = 20 I know the answer is (�2, 4) but I don't know why. Can someone please explain this to me?

SOLUTION: y = x^2 x^2 + y^2 = 20 I know the answer is (�2, 4) but I don't know why. Can someone please explain this to me?

Algebra.Com

Question 152180: y = x^2
x^2 + y^2 = 20
I know the answer is (�2, 4) but I don't know why. Can someone please explain this to me?
Answer by oscargut(2103) (Show Source): You can put this solution on YOUR website!
y = x^2
x^2 + y^2 = 20
let use 1st eq in 2nd eq
so y+(y^2)=20
y^2+y-20=0

then y=4 or y=-5
if y=-5 then x is not real
if y=4 then x^2=4 then x=2 or -2
solution is (2,4) and (-2,4)

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