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Lines and slopes

Problem 13.142 · easy

Find the equation of the line through \( \displaystyle (-4, -5) \) that is parallel to \( \displaystyle y = \frac{5 x}{2} - 3 \), in slope-intercept form.
  1. Parallel lines share a slope. The slope is 5/2.
    Reviewed
  2. \[ \frac{5 \left(x + 4\right)}{2} - 5 = \frac{5 x}{2} + 5 \]
    Point-slope form, then simplify.✓ Proved
  3. \[ \left. \frac{5 x}{2} + 5 \right|_{\substack{ x=-4 }} = -5 \]
    The line passes through (-4, -5).✓ Proved
Answer \( y = \frac{5 x}{2} + 5 \)

Lines: 2 proved, 1 reviewed. The answer was also checked a second way, without looking at the solution. The reviewers disagree about how one step is explained; every verdict is in the receipt. How we verify

The full receipt
LineStatusChecked byDetail
1Reviewedreviewers: gpt-oss:20b, qwen3.6:27b-mlxa sentence; read, not computed
2✓ Provedsympy 1.14.0simplify(lhs - rhs) reduced to 0
3✓ Provedsympy 1.14.0simplify(lhs - rhs) reduced to 0
answer, a second way✓ Checked independentlysympy 1.14.0 + mpmath 1.3.0the line meets the point with the required slope

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass — The solution correctly identifies the slope from the given line and uses the point-slope form to derive the correct equation. The verification step confirms the result.
Every verdict on record (6)
  • qwen3.6:27b-mlx: pass 2026-10-17 — The solution correctly identifies the slope from the given line and uses the point-slope form to derive the correct equation. The verification step confirms the result.
  • gpt-oss:20b: pass 2026-10-17
  • qwen3.6:27b-mlx: pass 2026-10-15 — The solution correctly identifies the slope and verifies the resulting equation passes through the given point. The algebraic steps are valid and the final answer is correct.
  • gpt-oss:20b: pass 2026-10-15
  • qwen3.6:27b-mlx: pass 2026-10-14 — The solution correctly identifies the slope and derives the correct equation. The verification step confirms the point lies on the line.
  • gpt-oss:20b: fail (misleading) 2026-10-14 — Sentence 2 incorrectly applies point‑slope form; it equates two expressions instead of writing y = (5/2)(x+4) – 5, which would then simplify to the correct line. The student would learn a flawed method.

Proved: SymPy reduced the difference between the two sides to zero. Checked independently: a separate method, named above, confirmed it. Checked numerically: the two sides agree at every sampled point, which is evidence, not proof. Reviewed: a model or a person read it; that is all a sentence can have. Solution by generator:structured/lines_slopes, checked 2026-10-17 with SymPy 1.14.0.