2025年9月国际A卷 · 第 5 题

2025年9月国际A卷 · 原库模块 2 · Q5 原库参考解析

The cost to rent a kayak consists of a fixed fee for the first hour and an hourly fee for each additional hour. The table shows the rental cost for 4 hours and for 6 hours.

Which function f gives the rental cost, in dollars, for x hours rental, where \( x\ge1 \)?