作业帮已知x+xy=20,xy+x= -10,求下列代数式的值1.3-4x-4xy+1/2xy+1/2y 2.x-y3.x+2xy+y
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/30 05:37:47
已知x+xy=20,xy+x= -10,求下列代数式的值1.3-4x-4xy+1/2xy+1/2y 2.x-y3.x+2xy+y
已知x+xy=20,xy+x= -10,求下列代数式的值
1.3-4x-4xy+1/2xy+1/2y 2.x-y
3.x+2xy+y
已知x+xy=20,xy+x= -10,求下列代数式的值1.3-4x-4xy+1/2xy+1/2y 2.x-y3.x+2xy+y
3-4x-4xy+1/2xy+1/2y
=3-80+1/2xy+1/2y
=3-80-5
=-82
x-y
=(x+xy)-(xy+y)
=20+10
=30
x+2xy+y
=(x+xy)+(xy+y)
=20-10
=10
已知条件有错? 大概是①x+xy=20
，②xy+y=-10吧!
1.3-4(x+xy)+1/2(xy+y)
=3-4x20+1/2(-10)
=-82
2.x-y
=①-②
=30
3.x+2xy+y
=(x+xy)+(xy+y)
=20-10
=10
x+xy=20,xy+x= -10,
不对
题目有问题····
已知x-xy=20,xy-y=-10,则x-y=( ),x+y-2xy=( ).
已知x-xy=20,xy-y=-10,则x-y=?,x+y-2xy?
已知x+xy=20,xy+x= -10,求下列代数式的值1.3-4x-4xy+1/2xy+1/2y 2.x-y3.x+2xy+y
已知x-xy=20,xy-y=12,则x-y= ,-2xy+x+y=
已知x-xy=20 xy-y=12,则x-y=（ ）,x+y-2xy=（ ）.
已知:x-xy=20,xy-y=12,则x-y=...,-2xy+x+y=...
已知x-xy=10,xy-y=2,则x-y=（ ）,-2xy+x+y=（ ）.
已知:x-xy=40,xy-y=-20,求代数式x-y和x+y-2xy的值.
已知x^2-xy=10,xy-y^2=20,求：x^2-2xy+y^2 的值2x^2+xy-3y^2 的值2x^2-5xy+3y^2 的值
已知x-xy=20,xy-y=-10,则x-y=__,x+y=__.
由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少?
已知x^2-xy=10,xy-y^2=20,求：x^2-y^2x^-2xy+y^2
|x|/x+y/|y|+xy/|xy|=
已知2x+xy=10,3y+2xy=6.求4x+8xy+9y=?
已知x+y=1,xy=-2,则x²y+xy²-2xy
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
已知xy>0,证明xy+xy/1+x/y+y/x>=4