Canonical URI: https://w3id.org/kmath/textbook_solution/jihak_solution_p153_p111_problem_02
| rdf:type | math:TextbookSolution |
|---|---|
| rdfs:label | 지학사 p111 문제 2 풀이 |
| rdfs:comment | 지학사 공통수학1 정답 및 해설 p153의 p111 문제 2 풀이. |
| math:answerText | \({}_{n-1}C_{r-1}+{}_{n-1}C_r={}_nC_r\). |
| math:explanationText | \({}_{n-1}C_{r-1}+{}_{n-1}C_r =\frac{(n-1)!}{(r-1)!(n-r)!}+\frac{(n-1)!}{r!(n-r-1)!} =\frac{(n-1)!\times r}{(r-1)!(n-r)!\times r} +\frac{(n-1)!\times(n-r)}{r!(n-r-1)!\times(n-r)} =\frac{(n-1)!\times r}{r!(n-r)!} +\frac{(n-1)!\times(n-r)}{r!(n-r)!} =\frac{n!}{r!(n-r)!}={}_nC_r\). |
| math:mappingConfidence | 1.0 |
| math:pageStart | 153 |
| math:problem | textbook_problem:jihak_vision_p111_problem_02 |
| math:reviewStatus | reviewed |
| math:solutionKind | worked_solution |
| math:usesSolutionPattern | solution_pattern:combination_pascal_identity |