The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 80.5586\\[1 em]x_2 &= -0.5586 \end{aligned} $$The solutions of $ 4x^2-320x-180 = 0 $ are: $ x = 40-\sqrt{ 1645 } ~ \text{and} ~ x = 40+\sqrt{ 1645 }$.
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