已知x+y=3,xy=-2,求(3x-4y+2xy)-(2x-5y+5xy)的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/27 14:17:17
![已知x+y=3,xy=-2,求(3x-4y+2xy)-(2x-5y+5xy)的值](/uploads/image/z/557159-23-9.jpg?t=%E5%B7%B2%E7%9F%A5x%2By%3D3%2Cxy%3D-2%2C%E6%B1%82%EF%BC%883x-4y%2B2xy%EF%BC%89-%EF%BC%882x-5y%2B5xy%EF%BC%89%E7%9A%84%E5%80%BC)
已知x+y=3,xy=-2,求(3x-4y+2xy)-(2x-5y+5xy)的值
已知x+y=3,xy=-2,求(3x-4y+2xy)-(2x-5y+5xy)的值
已知x+y=3,xy=-2,求(3x-4y+2xy)-(2x-5y+5xy)的值
(3x-4y+2xy)-(2x-5y+5xy)
=3x-4y+2xy-2x+5y-5xy
=x+y-3xy
=3-3x(-2)
=3+6
=9
祝学习进步,望采纳,不懂的欢迎追问...
(3x-4y+2xy)-(2x-5y+5xy)
=3x-4y+2xy-2x+5y-5xy
=3x-2x+5y-4y+2xy-5xy
=x+y-3xy
=3-3*(-2)
=3+6
=9
(3x-4y+2xy)-(2x-5y+5xy)
=3x-4y+2xy-2x+5y-5xy
=x+y-3xy
=3+6=9
原式=3x-4y+2xy-2x+5y-5xy=x+y-3xy=3-6=-3
(3x-4y+2xy)-(2x-5y+5xy)
=3x-2x-4y-(-5y)+2xy-5xy
=x+y-3xy
=3-3(-2)
=9