lean_workbook_plus_33924

Proved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

Let $a, b, c > 0$ . Prove $(a+b)^{3}+(2a+b)^{3}+(3a)^{3}\le 8(9a^{3}+b^{3})$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_33924 (a b c : ℝ) (ha : 0 < a) (hb : 0 < b) (hc : 0 < c) : (a + b) ^ 3 + (2 * a + b) ^ 3 + (3 * a) ^ 3 ≤ 8 * (9 * a ^ 3 + b ^ 3)   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook

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