✔ 最佳答案
In mathematics, the integers a and b are said to be coprime or relatively prime if they have no common factor other than 1 and −1, or equivalently, if their greatest common divisor is 1.
在數學上﹐兩個數a,b﹐若它們除了1和-1外再冇公因子﹐則它們是互質的
現在1和任一數x﹐除了1和-1外﹐再冇公因子
所以1和任一數x是互質的