来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/07/14 20:32:05
计算下列各题
![](http://img.wesiedu.com/upload/d/e6/de6b38e5b6bf034a6c5c71ac71421883.jpg)
解
原式
=(x^2-y)/(x-3)^2-(9-y)/(x-3)^2
=(x^2-y-9+y)/(x-3)^2
=(x^2-9)/(x-3)^2
=(x-3)(x+3)/(x-3)^2
=(x+3)/(x-3)
原式
=(a^2-1)/(a^2-2a)-(4a-5)/(a^2-2a)
=(a^2-1-4a+5)/(a^2-2a)
=(a^2-4a+4)/a(a-2)
=(a-2)^2/a(a-1)
=(a-2)/a