化简：（1）（a+2b)/(a+b)+2b的平方/a的平方-b的平方

(1)（a+2b)/(a+b)+2b²/(a²-b²)
=（a+2b)(a-b)/(a²-b²)+2b²/(a²-b²)
=(a²+ab-2b²+2b²)/(a²-b²)
=a(a+b)/[(a+b)(a-b)]
=a/(a-b)
(2)（x²-1）/(x²+2x+1)-（x+1)/(x-1)
=(x+1)(x-1)/(x+1)²-（x+1)/(x-1)
=(x-1)/(x+1)-（x+1)/(x-1)
=(x²-2x+1-x²-2x-1)/(x+1)(x-1)
=-4x/(x+1)(x-1)