So sánh 2 biểu thức E = 2024^99 − 1/2024^100 − 1 và F = 2024^98 − 1/2024^99 − 1
Giải thích
Ta có:
\(2024.E = 2024.\frac{{{{2024}^{99}} - 1}}{{{{2024}^{100}} - 1}} = \frac{{{{2024}^{100}} - 2024}}{{{{2024}^{100}} - 1}} = \frac{{{{2024}^{100}} - 1 - 2023}}{{{{2024}^{100}} - 1}} = 1 - \frac{{2023}}{{{{2024}^{100}} - 1}}\).
\(2024.F = 2024.\frac{{{{2024}^{98}} - 1}}{{{{2024}^{99}} - 1}} = \frac{{{{2024}^{99}} - 2024}}{{{{2024}^{99}} - 1}} = \frac{{{{2024}^{99}} - 1 - 2023}}{{{{2024}^{99}} - 1}} = 1 - \frac{{2023}}{{{{2024}^{99}} - 1}}\).
Mà \({2024^{99}} - 1 < {2024^{100}} - 1\) nên \(\frac{{2023}}{{{{2024}^{99}} - 1}} > \frac{{2023}}{{{{2024}^{100}} - 1}}\) suy ra \( - \frac{{2023}}{{{{2024}^{99}} - 1}} < - \frac{{2023}}{{{{2024}^{100}} - 1}}\)
Do đó \(2024.E > 2024.F\).
Vậy \(E > F\).