Question 1137839
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Replace y in the first equation by "3x", based on the second equation.


You will get


3x = x^2 + 6x + 9,

x^2 + 3x + 9 = 0,


which has no real solutions, since the discriminant  d = b^2 - 4ac = 3^2 - 4*9 = 9 - 36 = -27 is negative.


The equation has two solutions in complex numbers


{{{x[1,2]}}} = {{{(-3 +- 3*sqrt(3)*i)/2}}}.
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