# Root sum of roots.

\( \sqrt{a} + \sqrt{b} \) is root of a monic polynomial of grade 4 with integers coefficients \( x^4 +a_{3}x^3 +a_{2}x^2 + a_{1}x + a_{0} \) , where \( a \) and \( b \) are coprime integers. We know that \( a_{2} = -10 a_{0} \) and the sum of the coefficients is \( -2a -b \).

Find \( (a-4b)^2 \)