化简（a+b-根号ab分之a根号a+b根号b）+(a-2根号a分之根号a+2)÷(a-4分之根号a)
问题描述：
化简（a+b-根号ab分之a根号a+b根号b）+(a-2根号a分之根号a+2)÷(a-4分之根号a)
答
=(√a+√b)(a-√ab+b)/(a-√ab+b)+(√a+2)/√a(√a-2)×(√a+2)(√a-2)/√a
=√a+√b+(√a+2)²/a