x=（根号3）+1,y=（根号3）-1
xy=2
x+(根号xy)/[（根号xy)+y]+(根号xy)-y/x-(根号xy)
=(√3+√2+1)/(√3+√2-1)+(1+√2-√3)/(√3-√2+1)
=[(√3+√2+1)(√3-√2+1)]/[(√3+(√2-1))(√3-(√2-1))]+[(1+√2-√3)(1-√2+√3)]/[(√3+(√2-1))(√3-(√2-1))]
=[(√3+1)^2-2+1-(√2-√3)^2]/[3-(√2-1)^2]
=(2√3+√6-√2)/2