若x-y=1,xy=5,则x²y-xy²=?已知a+b=3,a²b+ab²=1,则ab=?
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 08:51:22
![若x-y=1,xy=5,则x²y-xy²=?已知a+b=3,a²b+ab²=1,则ab=?](/uploads/image/z/1730582-62-2.jpg?t=%E8%8B%A5x-y%3D1%2Cxy%3D5%2C%E5%88%99x%26%23178%3By-xy%26%23178%3B%3D%3F%E5%B7%B2%E7%9F%A5a%2Bb%3D3%2Ca%26%23178%3Bb%2Bab%26%23178%3B%3D1%2C%E5%88%99ab%3D%3F)
若x-y=1,xy=5,则x²y-xy²=?已知a+b=3,a²b+ab²=1,则ab=?
若x-y=1,xy=5,则x²y-xy²=?
已知a+b=3,a²b+ab²=1,则ab=?
若x-y=1,xy=5,则x²y-xy²=?已知a+b=3,a²b+ab²=1,则ab=?
解
x²y-xy²
=xy(x-y)
=5×1
=5
a²b+ab²=1
∴ab(a+b)=1
∵a+b=3
∴3ab=1
∴ab=1/3