{2x的平方-(x+y)(x-y)}{(z-x)(z+x)+(y+z)(y-z)}急!
①(x+y+z)(-x+y+z)(x-y+z)(x+y-z)
x分之y+z=y分之z+x=z分之x+y(x+y+z不等于0),求x+y+z分之x+y-z
因式分解x的平方(y-z)+y的平方(z-x)+z的平方(x-y)
(x-y+z)(x+y+z)等于多少.
x,y,z为正实数 x/(2x+y+z)+y/(x+2y+z)+z/(x+y+2z)
(x+y+z)*(-x+y+z)*(x-y+z)*(x+y-z)=
计算:(x+y+z)(-x+y+z)(x-y+z)(x+y-z).
1.设X ,Y,Z 成等差数列,代数式(X-Z)*(X-Z)+ 4(X-Y)(Z-Y)=
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/(除以)x-y+z的值.
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
x的平方+y的平方+z的平方)—2x+4y+6z+14=0求x+y+z的值