x³+y³+z³-3xyz=(x+y)³-3x²y-3xy²+z³-3xyz
=(x+y)³+z³-(3x²y+3xy²+3xyz)
=(x+y+z)[(x+y)²-(x+y)z+z²]-3xy(x+y+z)
=(x+y+z)[(x+y)²-(x+y)z+z²-3xy]
=(x+y+z)(x²+2xy+y²-xz-yz+z²-3xy)
=(x+y+z)(x²+y²+z²-xy-xz-yz)
x³+y³+z³-3xyz为什么等于(x+y+z)(x²+y²+z
1个回答
相关问题
-
若xyz不等于0,且(y+z)/x=(z+x)/y=(x+y)/z,求(y+z)(z+x)(x+y)/xyz的值?
-
若xyz不等于0,且满足(y+z)/x=(x+z)/y=(x+y)/z,求（y+z)（x+z)（x+y)/xyz的值
-
若xyz不等于0,且满足(y+z)/x=(x+z)/y=(x+y)/z,求（y+z)（x+z)（x+y)/xyz的值
-
(x+y-z)/z=(y+z-x)/x=(z+x-y)/y 求(x+y)(y+z)(z+x)/xyz
-
已知:(x+y)/z=(x+z)/y=(z+y)/x,且xyz不等于0,则分式(x+y)(x+z)(z+x)/xyz的值
-
当XYZ不等于0,且[Y+Z]/X=[Z+X]/Y=[X+Y]/Z,则（X+Z）（Z+X）（X+Y）/XYZ的值是多少?
-
当XYZ不等于0,且[Y+Z]/X=[Z+X]/Y=[X+Y]/Z,则（X+Z）（Z+X）（X+Y）/XYZ的值是多少?
-
(x+y)/3=(y+z)/5=(z+x)/4 ,xyz不等于0,求x:y:z
-
x+2y=z x-2y=3z 且xyz不等于,那么x:y:z
-
若xyz≠0,且满足(y+z)/x=(x+z)/y=(x+y)/z,求[(y+z)(x+z)(x+y)]/xyz的值.