So sánh A và B, biết: \(A = \frac{{{{2024}^{2024}} + 1}}{{{{2024}^{2025}} + 1}}\); \(B = \frac{{{{2024}^{2023}} + 1}}{{{{2024}^{2024}} + 1}}\).
Áp dụng: nếu \(\frac{a}{b} < 1\) thì \(\frac{a}{b} < \frac{{a + m}}{{b + m}}\left( {a,b,m \in {\mathbb{N}^*}} \right)\)
Vì \(A = \frac{{{{2024}^{2024}} + 1}}{{{{2024}^{2025}} + 1}} < 1\) nên
\(\begin{array}{l}A = \frac{{{{2024}^{2024}} + 1}}{{{{2024}^{2025}} + 1}} < \frac{{{{2024}^{2024}} + 1 + 2023}}{{{{2024}^{2025}} + 1 + 2023}}\\ = \frac{{{{2024}^{2024}} + 2024}}{{{{2024}^{2025}} + 2024}} = \frac{{2024\left( {{{2024}^{2023}} + 1} \right)}}{{2024\left( {{{2024}^{2024}} + 1} \right)}}\\ = \frac{{{{2024}^{2023}} + 1}}{{{{2024}^{2024}} + 1}} = B\end{array}\)
Vậy A < B









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