来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/07/18 00:08:13
化简求过程!数学题
![](http://img.wesiedu.com/upload/4/f2/4f252515381d6fa70deb8a4e49c443fb.jpg)
其中x=1,y=1/3
求过程
(9x^3-xy^2)/[(3x+y)(9x^2-6xy+y^2)]
=[x(9x^2-y^2)]/[(3x+y)(3x-y)^2]
=[x(9x^2-y^2)]/[(3x+y)(3x-y)(3x-y)]
=[x(9x^2-y^2)]/[(9x^2-y^2)(3x-y)]
=x/(3x-y)
当x=1 y=1/3时
原式=1/(3-1/3)
=1/(8/3)
=3/8