Como hago este polinomio

??x^2 + 6 ( x^2 -2 x + 5 ) ^(1/2) = 11 + 2 x.......sumando -2x y sumando 6 en ambos lados de la igualdad:
( x^2 -2 x + 5 ) + 6( x^2 -2 x + 5 ) ^(1/2)=16  ......nombrando y=( x^2 -2 x + 5 ) ^(1/2)
y^2+6y=16
y^2+6y-16=0
(y+8)(y-2)=0, entonces
( x^2 -2 x + 5 ) ^(1/2)=y=-8,2
1.( x^2 -2 x + 5 ) ^(1/2)=-8
( x^2 -2 x + 5 )=64
x^2 -2 x - 59=0
     1.x=(2+(4-4(-59))^(1/2))/2=1+4(15)^(1/2)
     2.x=....................................=1-4(15)^(1/2)
2.( x^2 -2 x + 5 ) ^(1/2)=2
( x^2 -2 x + 5 )=4
x^2 -2 x + 1=0
(x-1)^2=0
x=1  (raiz doble)