已知;x+Y=7.x—y=1 xx十yy=? xxxxyyyy=?
(x-y)(x+y)(xx-yy)=?
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
已知xx+yy+4x-6y+13=0,求(xx-2x)/xx+3yy的值.
已知(x+y)(x+y)=25,(x-y)(x-y)=9求xy与xx+yy的值
已知14(XX+YY+ZZ)=(X+2Y+3Z)^2,求X:Y:Z
已知 xx-2x+yy+6y+10=0 求x+y的值
已知XX+YY+4X-6Y+13=0,则X的Y次方是
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x=1/2 y=1/3 z=1/4 则(xx+yy-zz+2xy)/(xx-yy+zz-2xz) 得多少?
已知XX+YY=7 XY=-2 X= Y=?