lean_workbook_plus_53370

Proved

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

Find the value of $f(x+8) - f(x+7) - f(x+6) + f(x+5) - f(x+4) + f(x+3) + f(x+2) -f(x+1)$ , where $f(x) = 7x^3 + 23x + 18$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_53370 (f : ℤ → ℤ) (x : ℤ) (f_def : ∀ x, f x = 7 * x ^ 3 + 23 * x + 18) : f (x + 8) - f (x + 7) - f (x + 6) + f (x + 5) - f (x + 4) + f (x + 3) + f (x + 2) - f (x + 1) = 336   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook

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