原式=(x+1)²/(x+2)÷(x+1)(x-1)/(x-1)-x/(x+2)
=(x+1)²/(x+2)÷(x+1)-x/(x+2)
=(x+1)/(x+2)-x/(x+2)
=(x+1-x)/(x+2)
=1/(x+2)
=1/(√3-2+2)
=√3/3