若x-y=a,求1/a²﹙x²+y²-ax+ay-2xy-6a²﹚的值.
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 06:58:37
![若x-y=a,求1/a²﹙x²+y²-ax+ay-2xy-6a²﹚的值.](/uploads/image/z/6895680-24-0.jpg?t=%E8%8B%A5x-y%3Da%2C%E6%B1%821%EF%BC%8Fa%26%23178%3B%EF%B9%99x%26%23178%3B%EF%BC%8By%26%23178%3B%EF%BC%8Dax%EF%BC%8Bay%EF%BC%8D2xy%EF%BC%8D6a%26%23178%3B%EF%B9%9A%E7%9A%84%E5%80%BC.)
若x-y=a,求1/a²﹙x²+y²-ax+ay-2xy-6a²﹚的值.
若x-y=a,求1/a²﹙x²+y²-ax+ay-2xy-6a²﹚的值.
若x-y=a,求1/a²﹙x²+y²-ax+ay-2xy-6a²﹚的值.
1/a²﹙x²+y²-ax+ay-2xy-6a²﹚
=1/a²[ ﹙x²-2xy+y²-ax+ay-6a²﹚ ]
=1/a²[ (x-y) ²-a(x-y)-6a² ] ( 因为x-y=a)
=1/a²[a²-a² -6a²]
=-6
注:将题中的x-y代换成a即可