已知a=2005x+2004,b=2005x+2005,c=2005x+2006,则多项式a2+b2+c2-ab-bc-ac的值为( ) A.0 B.1 C.2 D.3
已知a=2005x+2004,b=2005x+2005,c=2005x+2006,则多项式a2+b2+c2-ab-bc-ac的值为( )
A. 0
B. 1
C. 2
D. 3
A. 0
B. 1
C. 2
D. 3
数学人气:296 ℃时间:2019-08-21 15:44:48
优质解答
由题意可知a-b=-1,b-c=-1,a-c=-2,所求式=12(2a2+2b2+2c2-2ab-2bc-2ca),=12[(a2-2ab+b2)+(b2-2bc+c2)+(a2-2ac+c2)],=12[(a-b)2+(b-c)2+(a-c)2],=12[(-1)2+(-1)2+(-2)2],=3.故选D....
我来回答
类似推荐
猜你喜欢
- 1Would you like to know ________ that teacher
- 2“她已经被邀请去参加玛丽的生日聚会了吗?”的英语翻译?
- 3英语翻译!”要用what's开头!
- 4给墓换偏旁并组词
- 5the biggest mistake made by beginners when they just first stsrted exercising is not the diet,not the postures in liftin
- 6ANN often does her homework in the evening —— —— ann often —— her home 填什么
- 71至9个数字填入九个小圆圈中,使大圆圈上的八个小圆圈的和等于小圆圈三个数相乘的积
- 8Lessons____at 8:00 in my school.I often stay ____home and listen_____music.
- 9代数式7-(a+b)的二次方的最大值
- 10有理数乘方运算的符号法则是什么