20092008²/(20092009²+20092007²-2)
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/27 18:22:51
20092008²/(20092009²+20092007²-2)20092008²/(20092009²+20092007²-2)2009
20092008²/(20092009²+20092007²-2)
20092008²/(20092009²+20092007²-2)
20092008²/(20092009²+20092007²-2)
20092008²/(20092009²+20092007²-2)
=20092008²/((20092008+1)²+(20092008-1)²-2)
=20092008²/(20092008²+2*20092008²*1+1²+20092008²-2*20092008²*1+1²-2)
=20092008²/(2*20092008²)
=1/2