ps图层蒙版怎么添加:因式分解(x+y+z)^3-(y+z-x)^3-(z+x-y)^3-(x+y-z)^3
来源:百度文库 编辑:查人人中国名人网 时间:2024/07/08 11:26:37
kkkkkkkkk
(x+y+z)^3-(y+z-x)^3-(z+x-y)^3-(x+y-z)^3
=((x+y+z)^3-(y+z-x)^3)-((z+x-y)^3+(x+y-z)^3)
=(x+y+z-y-z+x)((x+y+z)^2+(x+y+z)(y+z-x)+(y+z-x)^2)-
(z+x-y+x-z+y)((z+x-y)^2-(z+x-y)(x+y-z)+(x+y-z)^2)
=2x((x+y+z)^2+(x+y+z)(y+z-x)+(y+z-x)^2-(z+x-y)^2+(z+x-y)(x+y-z)-(x+y-z)^2)
=2x((x+y+z+z+x-y)(x+y+z-z-x+y)+(y+z-x+x+y-z)(y+z-x-x-y+z)+(x+y+z)(y+z-x)+(z+x-y)(x+y-z))
=2x(12yz)
=24xyz
x3-y3=(x-y)(x2+xy+y2) ①
x3+y3=(x+y)(x2-xy+y2) ②
(x+y+z)3-(y+z-x)3=2x[(x+y+z)2+(y+z)2-x2+(y+z-x)2] ③
(z+x-y)3+(x+y-z)3=2x[(z+x-y)2-x2+(y-z)2+(x+y-z)2] ④
3和4相减,相减之后用平方差公式~(1和2是立方和差公式)
2x[4y(x+z)+4yz+4y(z-x)]=2x*12yz=24xyz~
因式分解(x+y+z)^3-(y+z-x)^3-(z+x-y)^3-(x+y-z)^3
因式分解x^3(y^2-z^2)+y^3(z^2-x^2)+z^3(x^2-y^2)
(x-y-z)(x+y+z)
(x+y-z)(x-y+z)-(x-y-z)(x+y+z)
因式分解:(x+y+z)^5-x^5-y^5-z^5
因式分解:(x+y+z)^5-x^5-y^5-z^5.
已知3x-z=x+y+z=4x+2y-z,求x : y : z
已知x,y,z为正实数,y*y=x*z,求证:x*x+y*y+z*z>(x-y+z)*(x-y+z)
正数x,y,z, xyz(x+y+z)=1,则(x+y)(x+z)最小值?
若x : y : z =1 :3 :5 则x+3y-z /x-3y+z=? 若x /y+z=y /x+z=z /x+y=k 则k=?