已知X+Y=1.XY=1/5,求(XX+1)(YY+1)的值
已知x(x+1)-(xx+y)=3,求(xx+yy)/2-xy的值
已知2x=3y,求xy/xx+yy-yy/xx-yy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,
如果实数X,Y满足XX+YY=1,求(1+XY)(1-XY)的最大值和最小值
已知X+Y+Z=1,且XY+YZ+XZ=0,求XX+YY+ZZ的值?
已知xx+yy+4x-6y+13=0,求(xx-2x)/xx+3yy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(x+y)(x+y)=25,(x-y)(x-y)=9求xy与xx+yy的值
已知x-y=5,y-z=4,求xx+yy+zz-xy-yz-xz的值
已知xx+xy=1,xy-yy=-4,则xx+2xy-yy=
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