The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 6.1854\\[1 em]x_2 &= -10.1854 \end{aligned} $$The solutions of $ x^2+4x-63 = 0 $ are: $ x = -2-\sqrt{ 67 } ~ \text{and} ~ x = -2+\sqrt{ 67 }$.
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