y^2=xy=x^2
(-3x^y+2xy)-( )=4x^+xy
X²+2xy+y²/xy乘x²-2xy+y²/xy+y²=
已知x-y=4xy,则2x+3xy-2yx-2xy-y
已知x-xy=8,xy-y=-9,求x+y-2xy的值
由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少?
x^2+xy+x=36,y^2+xy+y=20,求x+y.
如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值.
已知:xy+x=-1,xy-y=-2.
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
(x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2
(x+2y-3xy)-(-2x-y+xy),其中x+y=,xy=-,求值.
已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.