lean_workbook_plus_23113

Proved

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

Let $a, b \ge 1.$ Prove that $ab(a + 2b - 10) + 8(a + b)\geq 9$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_23113 (a b : ℝ) (ha : 1 ≤ a) (hb : 1 ≤ b) : a * b * (a + 2 * b - 10) + 8 * (a + b) ≥ 9   :=  by sorry

Source