( x - 2x-1/x )÷(x-1)/(x^2-2x)
=(x²-2x+1)/x ×x(x-2)/(x-1)
=(x-1)²/x ×x/(x-2)/(x-1)
=(x-1)(x-2)
=x²-3x+2
=x²-3x-2 +4
∵x²-3x-2=0
∴原式=0+4
=4