计算：(a-2倍的根号ab+b)/(根号a-根号b)+b-a/根号a-根号b

Question

计算：(a-2倍的根号ab+b)/(根号a-根号b)+b-a/根号a-根号b

Answer 1

=(√a-√b)²/(√a-√b)-(√a+√b)(√a-√b)/(√a-√b)
=√a-√b-√a-√b
=-2√b