Factoring a fifth-degree equation

Proved

WorkbookSource.problem_44582

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

lean-workbooksource-checked

(Solution) $x^5-2x^2-9x-6=0\Leftrightarrow (x+1)^2(x-2)(x^2+3)=0$

Source: InternLM Lean-Workbook, record lean_workbook_44582; Apache-2.0. Complete source proposition preserved.

Preamble

import Mathlib
open Real Nat

Formal statement

theorem WorkbookSource.problem_44582 (x : ℝ) : x^5 - 2 * x^2 - 9 * x - 6 = 0 ↔ (x + 1)^2 * (x - 2) * (x^2 + 3) = 0  :=  by sorry

Source