化简:[1+N/M -M/(M-N)]÷[(1-N/M -M/(M+N)] ,

问题描述:

化简:[1+N/M -M/(M-N)]÷[(1-N/M -M/(M+N)] ,

[1+N/M -M/(M-N)]÷[(1-N/M -M/(M+N)]
=[1+n/m -﹙m-n+n﹚/﹙m-n﹚]÷[(1-n/m-﹙m+n-n﹚/(m+n)]
=[1+n/m -1-n/﹙m-n﹚]÷[(1-n/m-1+n/(m+n)]
=[n/m -n/﹙m-n﹚]÷[-n/m+n/(m+n)]
=n[1/m -1/﹙m-n﹚]÷n[-1/m+1/(m+n)]
=[1/m -1/﹙m-n﹚]÷[-1/m+1/(m+n)]
=﹣n/[m﹙m-n﹚]÷﹙﹣n﹚/[m(m+n)]
=﹙m+n﹚/﹙m-n﹚