1.已知a+10=b+9=c+8,求2a²+2b²+2c²-2ab-2bc-2ac的值

问题描述:

1.已知a+10=b+9=c+8,求2a²+2b²+2c²-2ab-2bc-2ac的值

2a²+2b²+2c²-2ab-2bc-2ac
=(a-b)^2+(b-c)^2+(c-a)^2
=1+1+4
=6