设
=(1,-2),
=(-3,4),
=(3,2)则
(+2)•=( )
A. (-15,12)
B. 0
C. -3
D. -11
人气:429 ℃ 时间:2020-05-13 03:13:58
解答
∵
+2=(1,-2)+2(-3,4)=(-5,6),
(+2)•=(-5,6)•(3,2)=-3,
故选C
推荐
- 已知b/a=1/3,且3a+2b=2/3.a和b各等于多少?
- 2的a次等于3,4的b次等于5,8的c次等于4,求8的a+c+2b次
- 若已知|a+2|+|b-3|+|c-4|=0,则式子a+2b+3c的值为_.
- 若|a-3|+|2b-1|+|1/2c-1|=0,则a+b+c等于多少?
- a+2b分之a-2b=3,a和b分别等于多少
- 5y-6分之5=12分之5,y等于
- 已知曲线C:X2+Y2-2X-2Y+1=0相切的直线L交X,Y轴的正半轴AB两点,O为原点,若|OA|=a,|OB|=b(a>2,b>2) (1)求
- 已知水流的速度是5千米/时,轮船顺水航行需5小时,逆水航行需7小时,则A,B两码头之间的航程是多少千米2379
猜你喜欢
- 如果黄赤交角变大,为什么温带范围会缩小?
- It's fun to have a picnic,but they must get everything r______.
- She hopes to live a ___(peace)life It's ___(proba
- Y=sin2x的最小正周期怎么算?
- His name is Tony Brown.We can call him .
- The best love is the care you give
- 根据数字猜成语:A.1,2,5,6,7,8,9,10
- 皇历上说的今天是黄道吉日,为什么后面却是忌:诸事不宜.