Find the greatest common divisor of 45 and 63.
Answer and explanation
Correct answer: A. 9
- Step 1: Use the Euclidean algorithm or prime factors: and .
- Step 2: The common part is , so the GCD is .
Answer
9.
Why not the others: 315: that is the least common multiple. 18: a common factor is repeated. 1: the numbers do share a common factor.
Practise more Properties of Integers.
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