x-1分之2÷(x²-1分之2+x+1分之1)a²-2a+1分之a+1÷(1+a-1分之2)

x-1分之2÷(x²-1分之2+x+1分之1)a²-2a+1分之a+1÷(1+a-1分之2)
x-1分之2÷(x²-1分之2+x+1分之1)
a²-2a+1分之a+1÷(1+a-1分之2)

x-1分之2÷(x²-1分之2+x+1分之1)a²-2a+1分之a+1÷(1+a-1分之2)
原式=2/(x-1) ÷[2/(x+1)(x-1) +(x-1)/(x+1)(x-1)]
=2/(x-1)÷(2+x-1)/(x+1)(x-1)
=2/(x-1)× (x-1)
=2
原式=(a+1)/(a-1)² ÷[(a-1)/(a-1) +2/(a-1)]
=(a+1)/(a-1)²÷[(a-1)+2]/(a-1)
=(a+1)/(a-1)²×(a-1)/(a+1)
=1/(a-1)

1/(√6-√5)=(√3+√2)/(√3+√2)(√3-√2)=√3+√2
1/(√n-√(n-1))=√n+√(n-1)
=√2-1+√3-√2+...+√2012-√2011=√2012-1
您的计算符号漏的和错的太多了。。。
打字不易，如满意，望采纳。