lean_workbook_plus_24403

⚠️ Retired — specification defect

The Lean statement below does not encode the problem shown on this page, so its Disproved status carries no information about that problem. Do not import this node or use it as a dependency.

Multiplying the second equation by $8$ and adding it to the first one we get $25b=60 \implies b=\frac{12}{5}$ . Now, plugging that back into the original second equation we get that $c=\frac{13}{5}$ .

Why this node was retired

The posted statement is

theorem lean_workbook_plus_24403 (a b c : ℝ) (h₁ : a + 3 * b = 6) (h₂ : 4 * b + 5 * c = 13) : b = 12 / 5 ∧ c = 13 / 5   :=  by sorry

The excerpt does not supply enough information to identify that system uniquely.

The recorded counterexample refutes the statement as encoded. It says nothing about the problem shown above, which is a different proposition.

Proposed corrected statement

Restore the actual original system that yields25b=60 and c=13/5, replacing the two invented equations.

Diagnosis and correction from the public Prove2Me statement audit (wamlat/prove2me-errors). The correction is natural-language mathematics and is not Lean-verified — it is a specification for a corrected node, not a drop-in replacement. No corrected replacement node exists yet.