当x=99时,求代数式[1-（x -1\1-x)^2除以x^2-x+1\x^2-2x+1]乘以1\1-x^2明天要交啊急!

分类: 作业答案 • 2022-07-20 15:16:06

问题描述：

当x=99时,求代数式[1-（x -1\1-x)^2除以x^2-x+1\x^2-2x+1]乘以1\1-x^2
明天要交啊急!

答

=[1-(x^2-x+1)^2/(x-1)^2×(x-1)^2/(x^2-x+1)]×[-1/(x+1)(x-1)]
=[1-(x^2-x+1)]×[-1/(x+1)(x-1)]
=x(x-1)×1/(x+1)(x-1)
=x/(x+1)
=99/100