x³-8y³-z³-6xyz

来源：学生作业帮编辑：神马作文网作业帮分类：数学作业时间：2024/11/12 15:20:27

x³-8y³-z³-6xyz
因式分解
还有：a²+b²+c²-2bc+2ca-2ab
(x+1)^4+(x^2-1)^2+(x_1)^4

x^3+y^3+z^3-3xyz
= (x+y)(x^2+y^2-xy)+z^3-3xyz
= (x+y)[(x+y)^2-3xy]+z^3-3xyz
= (x+y)^3-3xy(x+y)+z^3-3xyz
= (x+y)^3+z^3-3xy(x+y)-3xyz
= (x+y+z)[(x+y)^2+z^2-z(x+y)]-[3xy(x+y)+3xyz]
= (x+y+z)(x^2+y^2+2xy+z^2-xz-yz)-3xy(x+y+z)
= (x+y+z)(x^2+y^2+z^2-xy-xz-yz)
把上面的y换成-2y,z换成-z
得
x³-8y³-z³-6xyz
=(x-2y-z)(x^2+4y^2+z^2+2xy+xz-2yz)

2003x³=2004y³=2005z³,xyz＞0,且³√2003x² 已知x,y,z为正整数,且满足x³-y³-z³=3xyz,x²=2(y+z),求已知：x+y+z=1,x²+y²+z²=2,x³+y³+z³ 已知x+y+z=3,x²+y²+z²=19,x³+y³+z³ (x+y)²-（x³+y³)÷（x+y) x³y³-x²y²-xy+1 7-2xy-3x²y³+5x³y²z-9x⁴y³z&sup 数学整式除法计算:（1）（7x²y³－8x²y³z）÷8x²y&sup （x-y／x+2y）³ 3x³-【x³+(6x²-7x)-2(x³-3xy-4y)】,其中x=-1,y= 试说明代数式 x³y³ - 1/2x²y + y² - 2x³y&su xy³-8x²y-x³y²-y4次方中,按字母y的降次幂排列为?