SOLUTION: Find the solution of using substitution, elimination or Cramers Rule x^2+y^2=7 x-y^2=-1

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Question 102832: Find the solution of using substitution, elimination or Cramers Rule
x^2+y^2=7
x-y^2=-1
Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
X-Y^2=-1
X=Y^2-1
(Y^2-1)^2+Y^2=7
Y^4-2Y^2+1+Y^2-7=0
Y^4-Y^2-6=0
(Y^2-3)(Y^2+2)=0
Y^2-3=0
Y^2=3
Y=SQRT3
Y=1.732 ANSWER.
Y^2+2=0
Y^2=-2
Y=1.414i ANSWER.
USING THE EQUATION X=Y^2-1 WE SOLVE FOR X:
X=-2-1
X=-3 ANSWER.
X=3-1
X=2 ANSWER.