One of the most useful everyday chengyu — fully idiomatic in modern speech and writing. Frequent in business negotiations, legal contexts, pricing discussions, and family disputes. Pairs naturally with 解决方案, 价格, 规则, 条件.
grammar
Two synonymous pairs: 公平 (fair) + 合理 (reasonable). Chengyu built from two AB patterns where both halves mean almost the same thing are especially common in legal/business register: 合情合理, 名正言顺, etc.
