先化简再求值 （1+x）分之（x²+2x）÷{x-（x+1）分之2}-1,其中x=根号2+1分之1

x=1/(√2+1)=√2-1
原式=x(x+2)/(x+1)÷(x²+x-2)/(x+1)-1
=x(x+2)/(x+1)*(x+1)/(x+2)(x-1)-1
=x/(x-1)-1
=(x-x+1)/(x-1)
=1/(x-1)
=1/(√2-1-1)
=(√2+2)/(2-4)
=-(√2+2)/2