已知a=2009,b=2010,则分式(a+b)(a²+b²)/a⁴-b⁴

问题描述:

已知a=2009,b=2010,则分式(a+b)(a²+b²)/a⁴-b⁴

(a+b)(a²+b²)/a⁴-b⁴
=(a+b)(a²+b²)/(a2-b2)(a2+b2)
=(a+b)/(a2-b2)
=(a+b)/(a+b)(a-b)
=1/(a-b)
=1/(2009-2010)
=1/-1
=-1

原式=(a+b)(a²+b²)/[(a²+b²)(a+b)(a-b)
=1/(a-b)
=1/(2009-2010)
=-1