:{a+2/a的平方-2a+8/4-a的平方}除以{a-2/a}
=[(a+2)/a(a-2)-8/(a-2)(a+2)]÷(a-2)/a
=[(a²+4a+4-8a)/a(a-2)(a+2)]÷(a-2)/a
=(a-2)²/a(a-2)(a+2)×a/(a-2)
=1/(a+2)你确定你算对了吗？我肯定做对了