lean_workbook_plus_67324

Proved

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

Solve for $n$ in the equation $\frac{n(n+1)}{2}=36$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_67324 (n : ℕ) : n * (n + 1) / 2 = 36 ↔ n = 8   :=  by sorry

Source