已知:a=2006x+2007,b=2006x+2006.c=2006x+2005.求:2a方+2b方+2c方-2ab-2bc-2ac的值

问题描述:

已知:a=2006x+2007,b=2006x+2006.c=2006x+2005.求:2a方+2b方+2c方-2ab-2bc-2ac的值

2a方+2b方+2c方-2ab-2bc-2ac
=a方+b方-2ab+b方+c方-2bc+a方+c方-2ac
=(a-b)^2 + (b-c)^2 + (a-c)^2
=1+1+4=6