x=根号2+根号3x^2=(根号2+根号3)^2=2+2根号6+3=5+2根号6x的四次方-9x²-2根号3x+3=x^2*(x^2-9)-2根号3*(根号2+根号3)+3=(5+2根号6)(5+2根号6-9)-2根号6-6+3=(5+2根号6)(2根号6-4)-2根号6-3=24+2根号6-20-2根号6-...