Given
color(white)("XXX")color(green)((x-2)^2)+color(blue)((-x+6)^2)=color(brown)(32)
Expanding the left side
color(white)("XXX")color(green)(x^2-4x+4)+color(blue)(x^2-12x+36)=color(brown)(32)
Combining like terms
color(white)("XXX")2x^2-16x+40=color(brown)(32)
Dividing both sides by 2 to simplify
color(white)("XXX")x^2-8x+20=16
Converting to standard quadratic form
color(white)("XXX")color(red)1x^2color(magenta)(-8x)color(orange)(+4)=0
With no obvious (at least to me) rational factors:
Apply the quadratic formula
color(white)("XXX")x=(-color(magenta)b+-sqrt(color(magenta)b^2-4color(red)acolor(orange)c))/(2color(red)a)
color(white)("XXXXX")=(8+-sqrt(64-16))/2
color(white)("XXXXX")=4+-2sqrt(3)