1/x1-1/x2 怎么转化成x1 -x 2/x1x2

问题描述:

1/x1-1/x2 怎么转化成x1 -x 2/x1x2

(1/x1)-(1/x2)=(x2/(x1x2))-(x1/(x1x2))=(x2-x1)/(x1x2),通分不就好了