SOLUTION: x^2+y=21 -4x-y=0

Question 480424: x^2+y=21
-4x-y=0
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
x^2+y=21..........1
-4x-y=0...........2
From (1) y=21-x^2
substitute y in (2)
-4x-(21-x^2)=0
-4x-21+x^2=0
x^2-4x-21=0
x^2-7x+3x-21=0
x(x-7)+3(x-7)=0
(x-7)(x+3)=0
x=7 OR -3
when x = 7 y = -28 (7,-28)
when x= -3 y= 12 (-3,12)
m.ananth@hotmail.ca
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