集合A={(x,y,z) | |x|≤3,|y|≤4,|z|≤5,x,y,z∈Z}有多少个元素?

集合=A{(X,Y,Z)|x^2+y^2+z^2+4=xy+3y+2z,x,y,z∈R}中有（ ）个元素. X+Y+Z=200,1/3X+4Y+5Z=200,求X,Y,Z等于多少? (x+y-z)(x-y+z)= x/2=y/3=z/5 x+3y-z/x-3y+z 已知集合A=｛x|-2≤x≤a｝,B=｛y|y=2x+3,x∈A},C=｛z|z=x×x,x∈A},若集合C属于集合B, 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) (x+y+z)^5-(x+y-z)^5-(x+z-y)^5-(z+y-x)^5, x-3y+z=0,3x-2y-4z=0,则x:y:z=多少? X+Y+Z=? 1.设有比例式：x/(y+z)=y/(x+z)=z/(x+y),有比例性质,得x/(y+z)=y/(x+z)=z/(x+ 集合{x,y,z,w}中有多少个子集包含元素w x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少,