x^2-2=0
x^2=2
原式=x^2-2x+1+x^2/x+2
=2-2x+1+2/x+2
=(2x+4-2x^2-4x+x+2+2)/x+2
=(2x+4-4-4x+x+2+2)/(x+2)
=4-x/x+2
∵x^2=2
∴x=±√2
∴原式=5-3√2或5+3√2