Question

(x2-1/x2)-(x1-1/x1)通分结果怎么是(x2-x1)(1+1/x1x2)求过程，或

写在纸上，谢谢。

Answer 1

解：原式=（x2^)/x2-(x1^2-1)/x1
=[x1(x2^2-1)-(x1^2-1)x2]/x1x2
=[x1(x2^2)-x2(x1^2)+x2-x1]/x1x2
=[x1x1(x2-x1)+(x2-x1)]/x1x1
=(x2-x1)(x1x2+1)/x1x2
=(x2-x1)(1+1/x1x2)

Answer 2

2-1原式=（x2^)/x2-(x1^2-1)/x1
=[x1(x2^2-1)-(x1^2-1)x2]/x1x2
=[x1(x2^2)-x2(x1^2)+x2-x1]/x1x2
=[x1x1(x2-x1)+(x2-x1)]/x1x1
=(x2-x1)(x1x2+1)/x1x2
=(x2-x1)(1+1/x1x2)