已知a-b=2,a-c=1,求(2a-b-c)^2+(2b-a-c)^2+(2c-a-b)^2

问题描述:

已知a-b=2,a-c=1,求(2a-b-c)^2+(2b-a-c)^2+(2c-a-b)^2

2a-b-c)^2+(2b-a-c)^2+(2c-a-b)^2=(2+1)^2+(-4+1)^2+(-2+2)^2=18