已(X+Y)²=7,(X-Y)²=3 求X²+Y²=?X*Y=?
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/20 13:29:41
![已(X+Y)²=7,(X-Y)²=3 求X²+Y²=?X*Y=?](/uploads/image/z/12871597-13-7.jpg?t=%E5%B7%B2%EF%BC%88X%2BY%EF%BC%89%26%23178%3B%3D7%2C%28X-Y%29%26%23178%3B%3D3+%E6%B1%82X%26%23178%3B%2BY%26%23178%3B%3D%3FX%2AY%3D%3F)
已(X+Y)²=7,(X-Y)²=3 求X²+Y²=?X*Y=?
已(X+Y)²=7,(X-Y)²=3 求X²+Y²=?X*Y=?
已(X+Y)²=7,(X-Y)²=3 求X²+Y²=?X*Y=?
写纸上拍下来给你看看吧.
(X+Y)²=7 | (1)
(X-Y)²=3 | (2)
X²+Y²=[(1)+(2)]/2=5
x*y=[(1)-(2)]/4=1