HMMT 二月 2006 · 冲刺赛 · 第 7 题
HMMT February 2006 — Guts Round — Problem 7
题目详情
- [6] Find all real numbers x such that x + + = 10 . 2 3
解析
- Find all real numbers x such that ⌊ ⌋ ⌊ ⌋ x x 2 x + + = 10 . 2 3 √ Answer: − 14 2 Solution: Evidently x must be an integer. Well, there aren’t that many things to √ √ check, are there? Among positive x , 8 is too small and 9 is too big; among negative √ √ x, − 15 is too small and − 13 is too big.