Solving a quadratic expression for y

Proved

WorkbookSource.problem_23850

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

lean-workbooksource-checked

For, $x=a \longrightarrow 2a-3y+z^2=1 \longrightarrow y=\frac{1}{3}z^2+\frac{2a-1}{3}$

Source: InternLM Lean-Workbook, record lean_workbook_23850 (Apache-2.0). The complete source proposition and explicit variable declarations are preserved.

Preamble

import Mathlib
open Real Nat

Formal statement

theorem WorkbookSource.problem_23850 (x y z a : ℝ) (h₁ : x = a) (h₂ : 2 * a - 3 * y + z ^ 2 = 1) : y = 1 / 3 * z ^ 2 + (2 * a - 1) / 3  :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_23850; Apache-2.0

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