已知x^2+xy=3,xy+y^2=-2,则2x^2-xy-3y^2=
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/17 02:44:03
![已知x^2+xy=3,xy+y^2=-2,则2x^2-xy-3y^2=](/uploads/image/z/8784949-13-9.jpg?t=%E5%B7%B2%E7%9F%A5x%5E2%2Bxy%3D3%2Cxy%2By%5E2%3D-2%2C%E5%88%992x%5E2-xy-3y%5E2%3D)
xj1Ee1n2"(C$)ҩ
颊"-B7MuLޤ;on$s/%Jb4o+f86AD8
l aDŽٹVK(2`0ڨe!Zn2Ʃg/0x˫Oߟ)kzlÐB=AyXzSPU0aW(&?ʽ
已知x^2+xy=3,xy+y^2=-2,则2x^2-xy-3y^2=
已知x^2+xy=3,xy+y^2=-2,则2x^2-xy-3y^2=
已知x^2+xy=3,xy+y^2=-2,则2x^2-xy-3y^2=
x^2+xy=3可化为x(x+y)=3
xy+y^2=-2可化为y(x+y)=-2
两式相加减得(x+y)^2=1
(x+y)(x-y)=5
得{x+y=1 {x+y=-1
x-y=5 x-y=-5
这两个二元一次方程组
解得两组解{x1=3 {x2=-3
y1=-2 y2=2
代入2x^2-xy-3y^2可得唯一答案12
由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少?
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知xy^2=-2 求-xy(x^2y^5-xy^3-y)
已知xy^2=-2xy(x^2y^5-xy^3-y)
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
已知xy为正整数,3xy=2x+3y+5.求xy=?
已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.
已知x+xy+y=3,则(3x+2xy+3y)/(2x+xy+2y)=
已知x-y=3xy,则2x+3xy-2y除以x-2xy-y=?
已知x-y=3xy,则2x+3xy-2y/x-2xy-y=
已知y=3xy+x,求代数式2x+3xy-2y/x-2xy-y的值
已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值.
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知x-y=3xy,求2x+3xy-2y/x-2xy-y
已知x-y=3xy,求2x-3xy-2y/x-2xy-y
已知y=3xy+x,求代数式2x+3xy-2y/x-2xy-y的值
已知x+y=3xy,求2x+2y-xy/x+y+2xy的值、