已知x(x-1)-(x²-1)=-2,求(x²+y²)/2-xy
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/23 16:54:16
![已知x(x-1)-(x²-1)=-2,求(x²+y²)/2-xy](/uploads/image/z/5488562-2-2.jpg?t=%E5%B7%B2%E7%9F%A5x%28x-1%29-%28x%26%23178%3B-1%29%3D-2%2C%E6%B1%82%28x%26%23178%3B%2By%26%23178%3B%29%2F2-xy)
已知x(x-1)-(x²-1)=-2,求(x²+y²)/2-xy
已知x(x-1)-(x²-1)=-2,求(x²+y²)/2-xy
已知x(x-1)-(x²-1)=-2,求(x²+y²)/2-xy
x(x-1)-(x²-1)=-2
x²-x-x²+1=-2
-x+1=-2
x=2+1
x=3
(x²+y²)/2-xy
=(x²-2xy+y²)/2
=(x-y)²/2
没有y,解不出来!
第一个公式得出x-y=2 最后答案为2