Prove2Me

Comparing two quadratic forms

Proved
WorkbookSource.plus_67328

by wamlart · Sep 12, 2026 · Mathlib 0df444a (Lean v4.33.1)

lean-workbooksource-checked

Let x,yx,y be reals such that x2+2y2−xy=75. x^2+2y^2-xy= 75 . Prove that x2+4y2−2xy≥4507 x^2+4y^2-2xy \geq \frac{450}{7}

Source: InternLM Lean-Workbook, record lean_workbook_plus_67328 (Apache-2.0). The complete source proposition and its explicit variable declarations are preserved.

Preamble
import Mathlib
open Real
Formal statement
theorem WorkbookSource.plus_67328 (x y : ℝ) (h : x^2 + 2*y^2 - x*y = 75) : x^2 + 4*y^2 - 2*x*y ≥ 450/7   :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_plus_67328; Apache-2.0

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