lean_workbook_plus_5395

Proved

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

while $x \in (0,1)$ we have $\frac {(1 - x)^3}{1 + 2x}\geq \frac {116}{225} - \frac {76x}{75}$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_5395  (x : ℝ)
  (h₀ : 0 < x)
  (h₁ : x < 1) :
  (1 - x) ^ 3 / (1 + 2 * x) ≥ 116 / 225 - 76 * x / 75   :=  by sorry

Source