SOLUTION: x^2+y=18 -3x-y=0

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Question 480790: x^2+y=18
-3x-y=0
Answer by mananth(16946) About Me  (Show Source):
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x^2+y=18
y= 18-x^2
-3x-y=0
substitute y in the second equation
-3x-(18-x^2)=0
-3x-18x+x^2=0
x^2-3x-18=0
x^2-6x+3x-18=0
x(x-6)-3(x-6)=0
(x-6)(x-3) =0
x= 6 OR 3
when x=6, y=-18. (6,-18)
when x=3,y=9. (3,9)