(X平方-2X+3)平方=4X平方-8X+17令x^2-2x+3=tx^2-2x=t-3t^2=4(t-3)+17t^2-4t-5=0(t-5)(t+1)=0t=5或t=-1(1)x^2-2x+3=5x^2-2x=2(x-1)^2=3x=1+√3或x=1-√3(2)x^2-2x+3=-1x^2-2x+2=0,方程无解所以方程的根x=1+√3或x=1-...