化简下列分式（要过程）：
问题描述：
化简下列分式（要过程）：
1 x²+x÷x²-1 2.x²-9÷x²-6x+9 3.x²+4x÷x²+8x+16 4.ab²（a-b）÷a²b-ab²
5.x²-8x+16÷x²-16 6.x²-2x÷2y-xy
答
1.(x²+x)/(x²-1)=x(x+1)/(x+1)(x-1)=x/x-12.(x²-9)/(x²-6x+9)=(x+3)(x-3)/(x-3)²=(x+3)/(x-3)3.(x²+4x)/(x²+8x+16)=x(x+4)/(x+4)² =x/(x+4)4.ab²(a-b)/(a...