x^2-y^2 / x^2y+xy^2
=(x+y)(x-y)/xy(x+y)
=x-y/xy
=(根宴伏辩号3 +2-根号3 +2)/(根厅拦号晌缺3 +2)(根号3 - 2)
=4/-1
=-4
2x^2-2XY+Y^2-4X+4
=x^2-2XY+Y^2+x^2-4X+4
=(x-y)^2+(x-2)^2
=16+3
=19
^2-y^2 / x^2y+xy^2 =(x+y)(x-y) / xy(x+y)=(x-y)/xy
再把xy的值分别带做信进去镇庆即可
分子是√3 +2 -(√3-2)=4
分母是(√3 +2)*(√3-2)=-1
最后结御胡握果是-4