SOLUTION: I am having trouble solving this system using the substitution method. 2x + y = -1....then underneath x^2 = 4 + y. Thanks for your help!

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Question 79150: I am having trouble solving this system using the substitution method. 2x + y = -1....then underneath x^2 = 4 + y. Thanks for your help!
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
solving the first equation for y gives y=-1-2x ... substituting into the second equation gives x^2=4-1-2x or x^2+2x-3=0

factoring gives (x+3)(x-1)=0 so x=-3 and x=1 ... from the first equation; when x=-3, y=5 and when x=1, y=-3

these numbers check with the second equation