作业帮 > 数学 > 作业

越快分越多x的四次方+x³+x²-14(x+y)²+5-20(x+y-1)x²-

来源:学生作业帮 编辑:拍题作业网作业帮 分类:数学作业 时间:2024/04/28 17:47:44
越快分越多
x的四次方+x³+x²-1
4(x+y)²+5-20(x+y-1)
x²-y²-z²-2yz
9x的五次方-72x²y³
········

x^4+x³+x²-1
=x³(x+1)+(x²-1)
=x³(x+1)+(x-1)(x+1)
=(x+1)(x³+x-1)
4(x+y)²+5-20(x+y-1)
=4(x+y)²-20(x+y)+25
=[2(x+y)]²-2×2(x+y)×5+5²
=[2(x+y)-5]²
=(2x+2y-5)²
x²-y²-z²-2yz
=x²-(y²+z²+2yz)
=x²-(y+z)²
=[x-(y+z)][x+(y+z)]
=(x-y-z)(x+y+z)
9x^5-72x²y³
=9x²(x³-8y³)
=9x²[x³-(2y)³]————利用立方差公式
=9x²(x-2y)(x²+2xy+4y²)
不懂追问