reciprocal

The two countries established a reciprocal trade agreement to benefit their economies.

这两个国家建立了一个互惠的贸易协议，以促进各自的经济。

The reciprocal of 4 is 1/4, because 4 multiplied by 1/4 equals 1.

4的倒数是1/4，因为4乘以1/4等于1。