先化简,再求值： （2a减3b）（负2a减3b）加（负2a加b）的平方,其中a等于2分之1,b等于1
人气：306 ℃ 时间：2020-03-17 12:27:16
解答
（2a-3b）（-2a-3b）+（-2a+b）^2
=（-3b+2a）（-3b-2a）+（4a^2-4ab+b^2）
=（9b^2-4a^2）+（4a^2-4ab+b^2）
=10b^2-4ab带入数值=10-2=8
推荐
猜你喜欢
- Why don`t you talk to her about it 同义句__ __ talking to him about it?
- 坚持做一件事情就会成功,这句用一个四字成语概括
- 两捆电话线的长度相等,如果第一捆剪去20米,第二捆剪去4米,那么第二捆剩下的长度正好是第一捆余下长度的3
- You're shorter than me的问句 My legs are longer than yours的问句 She is 2years younger than you
- 已知三角形ABC中,A(2,-1),B(3,2),C(-3,-1),BC边上高为AD,求向量AD及D点坐标
- My father will come back in a week .同义句转换（ )( )a week ()my father comes back.
- I don't regret the things I've done,I regret the things I didn't do when I had the chance.不为做过
- 例句：书似阶梯,开启心灵之门；书似灯塔,照亮前行之路.仿句：(>_
