已知x^2-xy=10,xy-y^2=20,求:
已知:x-xy=40,xy-y=-20,求代数式x-y和x+y-2xy的值.
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知x^2-xy=10,xy-y^2=20,求:
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2x+xy=10,3y+2xy=6.求4x+8xy+9y=?
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=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知x+y=3xy,求2x+2y-xy/x+y+2xy的值、