已知x+y=2,xy=2,求12
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知x²-7xy+12y²=0求x²-xy+y²/2xy的值
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x:y=3:2,求(x²+3xy)/(xy+2xy)
已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
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、
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值.