Question

( x-9)^2 = -x^2+ 15x+ 50

Answer 1

$( x-9)^2 = -x^2+ 15x+ 50\\x^2-18x+81+x^2-15x-50=0\\2x^2-33x+31=0\\D=(-33)^2-4cdot2cdot31=1089-248=841\\sqrt D=sqrt{841}=29\\x_1=frac{33-29}{2cdot2}=frac{4}{4}=1\\x_2=frac{33+29}{2cdot2}=frac{62}{4}=15,5$