(1)若x+y=4,xy=3,求(x-y)的2次方的值 (2)(x-1)(x+1)(x 的2次方-1)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/22 07:13:36
![(1)若x+y=4,xy=3,求(x-y)的2次方的值 (2)(x-1)(x+1)(x 的2次方-1)](/uploads/image/z/2108848-40-8.jpg?t=%EF%BC%881%EF%BC%89%E8%8B%A5x%2By%3D4%2Cxy%3D3%2C%E6%B1%82%EF%BC%88x-y%EF%BC%89%E7%9A%842%E6%AC%A1%E6%96%B9%E7%9A%84%E5%80%BC+%EF%BC%882%EF%BC%89%EF%BC%88x-1%29%EF%BC%88x%2B1%EF%BC%89%EF%BC%88x+%E7%9A%842%E6%AC%A1%E6%96%B9-1%EF%BC%89)
(1)若x+y=4,xy=3,求(x-y)的2次方的值 (2)(x-1)(x+1)(x 的2次方-1)
(1)若x+y=4,xy=3,求(x-y)的2次方的值 (2)(x-1)(x+1)(x 的2次方-1)
(1)若x+y=4,xy=3,求(x-y)的2次方的值 (2)(x-1)(x+1)(x 的2次方-1)
(x-y)²
=x²-2xy+y²
=x²+2xy+Y²-4xy
=(x+y)²-4xy
=4²-4×3
=4
(x-1)(x+1)(x ²-1)
=(x²-1)(x²-1)
=x的4次方-2x²+1