20092008²/(20092009²+20092007²-2)

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/05 23:12:10
20092008²/(20092009²+20092007²-2)

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