【2005分之一+2006分之一+2007分之一+2008分之一分之一说明原因】

网友回答

令a=2006.5
则原式=(a^2-0.25)(a^2-2.25)/[(a^2-0.25)(a+1.5)+(a^2-2.25)(a+0.5)+(a^2-2.25)(a-0.5)+(a^2-0.25)(a-1.5)
=(a^2-0.25)(a^2-2.25)/[(a^2-0.25)(a+1.5+a-1.5)+(a^2-2.25)(a-0.5+a+0.5)]
=(a^2-0.25)(a^2-2.25)/[2a(a^2-0.25)+2a(a^2-2.25)]
=(a^2-0.25)(a^2-2.25)/[2a(a^2-0.25+a^2-2.25)]
=(a^2-0.25)(a^2-2.25)/[2a(2a^2-2.5)]
=(a^2-0.25)(a^2-2.25)/[2a(2a^2-2.5)]
好象是这样.
======以下答案可供参考======
供参考答案1:
令a=2006.5
则原式=(a^2-0.25)(a^2-2.25)/[(a^2-0.25)(a+1.5)+(a^2-2.25)(a+0.5)+(a^2-2.25)(a-0.5)+(a^2-0.25)(a-1.5)
=(a^2-0.25)(a^2-2.25)/[(a^2-0.25)(a+1.5+a-1.5)+(a^2-2.25)(a-0.5+a+0.5)]
=(a^2-0.25)(a^2-2.25)/[2a(a^2-0.25)+2a(a^2-2.25)]
=(a^2-0.25)(a^2-2.25)/[2a(a^2-0.25+a^2-2.25)]
=(a^2-0.25)(a^2-2.25)/[2a(2a^2-2.5)]
=(a^2-0.25)(a^2-2.25)/[2a(2a^2-2.5)]
你自己再算吧,OK?