The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 75535.9999\\[1 em]x_2 &= 0.0001 \end{aligned} $$The solutions of $ x^2-75536x+7 = 0 $ are: $ x = 37768-3 \sqrt{ 158491313 } ~ \text{and} ~ x = 37768+3 \sqrt{ 158491313 }$.
You can use step-by-step quadratic equation solver to see a detailed explanation on how to solve this quadratic equation.