Derivative of \( \displaystyle 10 x \left(2 x - 3\right) \)
Problem 2.1377 · medium
Differentiate \( \displaystyle f(x) = 10 x \left(2 x - 3\right) \).
- \[ \frac{d}{d x} 10 x \left(2 x - 3\right) \]derivativeStart with the derivative of the function.✓ Proved
- \[ = \frac{d}{d x} \left(20 x^{2} - 30 x\right) \]algebra algebraDistribute the terms inside the parentheses. Simplify the coefficients.✓ Proved
- \[ = - \frac{d}{d x} 30 x + \frac{d}{d x} 20 x^{2} \]sumApply the difference rule.✓ Proved
- \[ = - 30 \frac{d}{d x} x + 20 \frac{d}{d x} x^{2} \]constant-multipleFactor out the constants.✓ Proved
- \[ = 40 x - 30 \]power algebraDifferentiate the power terms. Multiply the remaining terms.✓ Proved
Answer \( 40 x - 30 \)
✓ Nihil obstat Every line of this solution was proved by the computer algebra system SymPy. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation.
The full receipt
| Line | Status | Checked by | Detail |
|---|---|---|---|
| 1 | ✓ Proved | sympy 1.14.0 | line 1 is the problem as stated |
| 2 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 3 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 0 |
| answer, a second way | ✓ Proved | sympy 1.14.0 | SymPy differentiated f directly and got the stated answer |
Reviewers
gpt-oss:20b: passqwen3.6:27b-mlx: pass — The solution correctly applies the rules in the specified vocabulary, with each step changing only one aspect of the expression. The labels accurately reflect the operations performed.
Every verdict on record (4)
qwen3.6:27b-mlx: pass 2026-10-03 — The solution correctly applies the rules in the specified vocabulary, with each step changing only one aspect of the expression. The labels accurately reflect the operations performed.gpt-oss:20b: pass 2026-10-03qwen3.6:27b-mlx: pass 2026-10-03gpt-oss:20b: pass 2026-10-03
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
gemma4:26b, checked 2026-10-03 with SymPy 1.14.0.