（20102009²+1）/[(20102009-1)²+(20102009+1)²]
=（20102009²+1）/[20102009²－2×20102009＋1²＋20102009²＋2×20102009＋1²]
=(20102009²+1)/(2×20102009²+2)
=(20102009²+1)/[(20102009²+1)×2]
=1/2
简便运算,仅限初一知识,限五分钟内解决 20102009²+1/20102008²+20102010
（20102009²+1）/[(20102009-1)²+(20102009+1)²]
=（20102009²+1）/[20102009²－2×20102009＋1²＋20102009²＋2×20102009＋1²]
=(20102009²+1)/(2×20102009²+2)
=(20102009²+1)/[(20102009²+1)×2]
=1/2