what is the lcm 12 and 36
What is the LCM of 12 and 36?
Answer:
To find the least common multiple (LCM) of two numbers like 12 and 36, we need to determine the smallest number that is a multiple of both. There are multiple approaches to find the LCM, including listing multiples, using prime factorization, or employing the greatest common divisor (GCD) method. We’ll explore two common methods: prime factorization and using the relation between the GCD and LCM.
Method 1: Prime Factorization
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Prime Factorization: Break down each number into its prime factors.
- The prime factorization of 12 is:12 = 2^2 \times 3^1
- The prime factorization of 36 is:36 = 2^2 \times 3^2
- The prime factorization of 12 is:
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Identify the Largest Power of Each Prime Number: For each prime number that appears in the factorizations, take the highest power from either number.
- For 2, the highest power is 2^2.
- For 3, the highest power is 3^2.
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Calculate the LCM: Multiply these highest powers together.
\text{LCM} = 2^2 \times 3^2 = 4 \times 9 = 36
Method 2: Using the GCD
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Find the GCD: The greatest common divisor (GCD) of two numbers can also help determine the LCM. We use the relationship:
\text{LCM}(a, b) = \frac{|a \times b|}{\text{GCD}(a, b)}-
First, find the GCD of 12 and 36:
Using the prime factorization method:
- The common prime factors of 12 and 36 are 2^2 and 3^1.
- Thus, \text{GCD} = 2^2 \times 3^1 = 4 \times 3 = 12.
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Calculate the LCM Using the GCD: Substitute the values into the LCM formula.
\text{LCM}(12, 36) = \frac{12 \times 36}{12} = 36
Final Answer:
The least common multiple (LCM) of 12 and 36 is 36.