a+b=3,ab=-2,求a³+2a²b+2ab²+b³的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 17:44:40
![a+b=3,ab=-2,求a³+2a²b+2ab²+b³的值](/uploads/image/z/2769546-66-6.jpg?t=a%2Bb%3D3%2Cab%3D-2%2C%E6%B1%82a%26%23179%3B%2B2a%26%23178%3Bb%2B2ab%26%23178%3B%2Bb%26%23179%3B%E7%9A%84%E5%80%BC)
a+b=3,ab=-2,求a³+2a²b+2ab²+b³的值
a+b=3,ab=-2,求a³+2a²b+2ab²+b³的值
a+b=3,ab=-2,求a³+2a²b+2ab²+b³的值
a³+2a²b+2ab²+b³
=a³+b³+2a²b+2ab²
=(a+b)(a²-ab+b²)+2ab(a+b)
=(a+b)(a²+ab+b²)
=(a+b)[(a+b)²-ab]
=3(3²+2)
=3×11
=33