Canonical URI: https://w3id.org/kmath/textbook_solution/visang_solution_p159_workbook_p138_08
| rdf:type | math:TextbookSolution |
|---|---|
| rdfs:label | 비상 p138 수학 익힘책 III-08 풀이 |
| rdfs:comment | 비상 공통수학1 정답 및 해설 p159의 수학 익힘책 p138 III-08 풀이. |
| math:answerText | \(5\) |
| math:explanationText | \({}_{n+1}C_{n-1}={}_{n+1}C_2\)이므로 문제의 등식은 \[ \frac{(n+2)(n+1)n}{3!}-2\times\frac{n(n-1)}{2!} = \frac{(n+1)n}{2!} \] \[ n^3-6n^2+5n=0,\quad n(n-1)(n-5)=0 \] 따라서 \(n\ge2\)이므로 \(n=5\). |
| math:mappingConfidence | 1.0 |
| math:pageStart | 159 |
| math:problem | textbook_problem:visang_workbook_p138_08 |
| math:reviewStatus | reviewed |
| math:solutionKind | worked_solution |
| math:usesSolutionPattern | solution_pattern:combination_symmetry |
| math:usesSolutionPattern | solution_pattern:permutation_combination_formula_substitution |