题目内容：

a-1分之2+a²-1分之a²-4a+4÷a+1分之a-1,其中a等于1加根号2

优质解答

原式=2/(a-1)+(a-2)²/[(a+1)(a-1)]×(a+1)/(a-1)=2/(a-1)+(a-2)²/(a-1)²=2(a-1)/(a-1)²+(a-2)²/(a-1)²=(2a-2+a²-4a+4)/(a-1)²=(a²-2a+2)/(a-1)²=[(a-1)²+1]...