已知x(x-1)-(xx-y)=-3求xx+yy-2xy
已知2x=3y,求xy/xx+yy-yy/xx-yy的值
已知x(x+1)-(xx+y)=3,求(xx+yy)/2-xy的值
x(x+1)-(xx+y)=-3,求(xx+yy)/2-xy的值
已知x,y是实数,且适合方程(xx+xy-12)(xx+xy-12)+(xy-2yy-1)(xy-2yy-1)=0求x,
已知xx+yy+4x-6y+13=0,求(xx-2x)/xx+3yy的值.
已知x=1/2 y=1/3 z=1/4 则(xx+yy-zz+2xy)/(xx-yy+zz-2xz) 得多少?
已知14(XX+YY+ZZ)=(X+2Y+3Z)^2,求X:Y:Z
已知(x+y)(x+y)=25,(x-y)(x-y)=9求xy与xx+yy的值
初二数学因式分解已知x-y+1的绝对值与xx+8x+16互为相反数,求xx+2xy+yy的值
已知,x/3 = y/1 = z/2 ,求 2xx - 2yy + 5zz /xy + yz +zx 的值.(/表示分数
已知XX+YY=7 XY=-2 X= Y=?
已知X+Y+Z=1,且XY+YZ+XZ=0,求XX+YY+ZZ的值?