x＾2-9y＾2+4z＾2+4xz

x＾2-9y＾2+4z＾2+4xz x+2z =3y 判断xx-9y+4zz+4xz是否是定值 已知：x+2z=3y,试求x^2-9y+4z^2+4xz的值 设3y=x+2z,求x²-9y²+4z²+4xz的值 已知3y=x+2z,求x平方-9y平方+4z平方+4xz 已知-3y=x+2z,求x²-9y²+4z²+4xz的值 (2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ) 若x/3=y=z/4,且xy+xz+yz=76,求2x*x+12y*y+9z*z的值 若x/2=1/y=z/3,且xy+xz+yz=99,求4x^2-2xz+3yz-9y^2的值. 如果3y=x+2y,那么x *x+9*y*y+4*z*z-6xy-12yz+4xz的值是多少? x^2+y^2+xy=25/4,x^2+z^2+xz=169/4,y^2+z^2+yz=36,求xy+xz+yz 设x-3y+2z=0,是说明x^2-9y^2+4z^2+4z^2+4xz+1为定值 化简(2x-y-z/x^2-xy-xz+yz)+(2y-x-z/y^2-xy-yz+xz)+(2x-x-y/z^2-xz-yz+xy) 已知x:4=y:5=z:6,求x^2+y^2-z^2/xy+xz+yz 已知XY+X/X+Y+1=2 XZ+2X/X+Z+2=3 (Y+1)(Z+2)/Y+Z+3=4 求X+Y+Z的值已知(XY+X)/(X+Y+1)=2 (XZ+2X)/(X+Z+2)=3 [(Y+1)(Z+2)]/(Y+Z+3)=4 求X+Y+Z的值 若x>y>z>0,求证：x-z+27/[(x+z)y-xz-y^2]≥9 三元二次方程组(XY+X)/(X+Y+1)=2(XZ+2X)/(X+Z+2)=3(Y+1)(Z+2)/(Z+Y+3)=4 因式分解 3x^2-11xy+6y^2-xz-4yz-2z^2