lean_workbook_plus_78528

Proved

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

For all real $x,y,z$ prove that $5(x^2+y^2+z^2)\geq 6xy-8xz+8yz$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_78528 : ∀ x y z : ℝ, 5 * (x ^ 2 + y ^ 2 + z ^ 2) ≥ 6 * x * y - 8 * x * z + 8 * y * z   :=  by sorry

Source