化简【x²-2y²-z²】-【-y²+3x²-z²】+【5x
(x-3y+2z)²=
若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值
已知x y z 满足x+y=5,z²=xy+y-9,求x+2y+3z的值
已知实数x,y,z,满足x+y=5,z²=xy+y=9,求x+2y+3Z的值
x³+y³+z³-3xyz为什么等于(x+y+z)(x²+y²+z
已知x,y,z满足方程组x-2y+z=0 7x+4y-5z=0,且z不等于0,2x²-3y²+z
若3x-2y-z=0,x+4y-3z=0,求3x²+y²/4x²-y²+z
已知x²+y²+z²-2x+4y-6z+14=0,求x+y-z/x+y+z的值
已知x,y,z满足x+y+2z=1,x²+y²+6z+1.5=0,求x,y,z的值
已知4x-5y+2z=0,x+4y-3z=0,求(x²+y²+z²)/xy+yz+xz
已知丨X+2丨+(Y-3)² =0 且(5分之X-2Y+Z)+5=½Y+X+Z 求Z
已知x²+y²-6x+2y+|z+3|+10=0,求x+z-y的值