①已知x+y=6,x²-y²=5,求x-y的值 ②若x+y=3,x²+y²=5,求xy的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 06:56:50
![①已知x+y=6,x²-y²=5,求x-y的值 ②若x+y=3,x²+y²=5,求xy的值](/uploads/image/z/2108233-1-3.jpg?t=%E2%91%A0%E5%B7%B2%E7%9F%A5x%2By%3D6%2Cx%26%23178%3B-y%26%23178%3B%3D5%2C%E6%B1%82x-y%E7%9A%84%E5%80%BC+%E2%91%A1%E8%8B%A5x%2By%3D3%2Cx%26%23178%3B%2By%26%23178%3B%3D5%2C%E6%B1%82xy%E7%9A%84%E5%80%BC)
①已知x+y=6,x²-y²=5,求x-y的值 ②若x+y=3,x²+y²=5,求xy的值
①已知x+y=6,x²-y²=5,求x-y的值 ②若x+y=3,x²+y²=5,求xy的值
①已知x+y=6,x²-y²=5,求x-y的值 ②若x+y=3,x²+y²=5,求xy的值
①x-y=(x²-y²)÷(x+y)=5÷6=5/6
②2xy=(x+y)²-(x²+y²)
2xy=3×3-5
2xy=4
xy=2