lean_workbook_plus_58298

Disproved

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

Prove that $(ab+bc+ca)(a+b+c) \leq \frac{9}{8}(a+b)(b+c)(c+a)$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_58298 : ∀ a b c : ℝ, (a * b + b * c + c * a) * (a + b + c) ≤ (9 / 8) * (a + b) * (b + c) * (c + a)   :=  by sorry

Source