{[(a-2)/a(a+2)]-[(2a-1)/(a-2)(a+2)]}÷(a+2)(a-1)/(a+2)^2先分解因式,再约掉（a+2）这个公因式=[(a-2）/a-（2a-1）/（a-2)]÷(a-1）通分=（-a^2-3a+4)÷a(a-2)(a-1)分子分解因式-（a+4)(a-1),分子分母约去（a-1)结...