lean_workbook_plus_40380

Proved

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

solBefore = 1 acre = x tons of potatoes\nAfter = 1 acre = x+4 tons of potatoes\n $360(x+4)=400x+640$ \nx=20

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_40380 (x : ℝ) : 360 * (x + 4) = 400 * x + 640 ↔ x = 20   :=  by sorry

Source