因式分解:1/(x平方-1)+1/(x平方+4x+3)+1/(x平方+8x+15)+1/(x平方+12x+35)
问题描述：
因式分解:1/(x平方-1)+1/(x平方+4x+3)+1/(x平方+8x+15)+1/(x平方+12x+35)
答
1/(x平方-1)+1/(x平方+4x+3)+1/(x平方+8x+15)+1/(x平方+12x+35)=1/(x+1)(x-1)+1/(x+1)(x+3)+1/(x+3)(x+5)+1/(x+5)(x+7)=1/2{1/(x-1)-1/(x+1)}+1/2{1/(x+1)-1/(x+3)}+1/2{1/(x+3)-1/(x+5)}+1/2{1/(x+5)-1/(x+7)}=1/2{...