分式3x\(x-4y)与(x+y)\(4y-x)的和减去7y\(x-4y)所得的差为?

分类: 作业答案 • 2021-12-20 06:04:30

问题描述：

答

=(3x-x-y-7y)/(x-4y)=2

答

3x/(x-4y)+(x+y)/(4y-x)-7y/(x-4y)
=3x/(x-4y)-(x+y)/(x-4y)-7y/(x-4y)
=(3x-x-y-7y)/(x-4y)
=(2x-8y)/(x-4y)
=2