首页 > 留学知识库

问题: (81-x^4)/(x^2+9)/(X-3)=

要有个过程,谢谢

解答:

(81-x^4)/(x^2+9)/(X-3)
=(9+x^2)(9-x^2)/(x^2+9)/(X-3)
=(9-x^2)/(x-3)
=(3-x)(3+x)/-(3-x)
=-x-3