题目内容
先化简,再求值:(3x+y)(x-4y)+(x-2y)2-4x(x-3y),其中x=-
,y=
.
| 1 |
| 6 |
| 2 |
| 3 |
原式=3x2-12xy+xy-4y2+x2-4xy+4y2-4x2+12xy=-3xy,
当x=-
,y=
时,原式=-3×(-
)×
=
.
当x=-
| 1 |
| 6 |
| 2 |
| 3 |
| 1 |
| 6 |
| 2 |
| 3 |
| 1 |
| 3 |
练习册系列答案
相关题目
题目内容
| 1 |
| 6 |
| 2 |
| 3 |
| 1 |
| 6 |
| 2 |
| 3 |
| 1 |
| 6 |
| 2 |
| 3 |
| 1 |
| 3 |