by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)
Prove that if a,b,c>0, then \n 21(a2+b2+c2+a+b+c9abc−2ab−2bc−2ca)+47((a−b)2+(b−c)2+(c−a)2)≥0
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_80259 {a b c : ℝ} (ha : a > 0) (hb : b > 0) (hc : c > 0) : (1 / 2) * (a ^ 2 + b ^ 2 + c ^ 2 + (9 * a * b * c) / (a + b + c) - 2 * a * b - 2 * b * c - 2 * c * a) + (7 / 4) * ((a - b) ^ 2 + (b - c) ^ 2 + (c - a) ^ 2) ≥ 0 := by sorry