已知a+x2=2009,b+x2=2010,c+x2=2011,且abc=6030.则a/bc+b/ca+c/ba-1/a-1/b-1/c=?
问题描述:
已知a+x2=2009,b+x2=2010,c+x2=2011,且abc=6030.则a/bc+b/ca+c/ba-1/a-1/b-1/c=?
答
a/bc+b/ca+c/ba-1/a-1/b-1/c=(a^2+b^2+c^2-ab-bc-ac)/abc
==(2a^2+2b^2+2c^2-2ab-2bc-2ac)/2abc
=[(a-b)^2+(b-c)^2+(a-c)^2]/2abc
=1/2010