The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 3+\sqrt{ 6 }i\\[1 em]x_2 &= 3-\sqrt{ 6 }i \end{aligned} $$The solutions of $ x^2-6x+15 = 0 $ are: $ x = 3+\sqrt{ 6 }i ~ \text{and} ~ x = 3-\sqrt{ 6 }i$.
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