Two numbers have prime factorizations of 2 2 · 3 · 5 and 2 · 3 2 · 5.

Which expressions will give the greatest common factor and the least common multiple?

GCF 2 · 3 · 5; LCM 2 2 · 3 2 · 5
GCF 2 2 · 3 2; LCM 2 2 · 3 2 · 5 2
GCF 2 · 3; LCM 2 · 3 · 5
GCF 2 2 · 3 2 · 5; LCM 2 · 3

1 answer

To find the GCF (greatest common factor) and LCM (least common multiple) of the two numbers with the given prime factorizations, let's first write down the prime factorizations clearly:

  1. The first number's factorization is: \( 2^2 \cdot 3^1 \cdot 5^1 \)
  2. The second number's factorization is: \( 2^1 \cdot 3^2 \cdot 5^1 \)

Finding the GCF (Greatest Common Factor):

To find the GCF, we take the lowest power of each prime factor present in both factorizations.

  • For the prime \(2\): the lowest power is \(2^1\).
  • For the prime \(3\): the lowest power is \(3^1\).
  • For the prime \(5\): the lowest power is \(5^1\).

So, the GCF is: \[ GCF = 2^1 \cdot 3^1 \cdot 5^1 = 2 \cdot 3 \cdot 5 \]

Finding the LCM (Least Common Multiple):

To find the LCM, we take the highest power of each prime factor present in the factorizations.

  • For the prime \(2\): the highest power is \(2^2\).
  • For the prime \(3\): the highest power is \(3^2\).
  • For the prime \(5\): the highest power is \(5^1\).

So, the LCM is: \[ LCM = 2^2 \cdot 3^2 \cdot 5^1 \]

Final Results:

  • GCF = \( 2^1 \cdot 3^1 \cdot 5^1 \) = \( 2 \cdot 3 \cdot 5 \)
  • LCM = \( 2^2 \cdot 3^2 \cdot 5^1 \)

Now we can match these results to the provided options:

  1. GCF 2 · 3 · 5; LCM 2² · 3² · 5
  2. GCF 2² · 3²; LCM 2² · 3² · 5²
  3. GCF 2 · 3; LCM 2 · 3 · 5
  4. GCF 2² · 3² · 5; LCM 2 · 3

From our calculations, the correct expressions are:

GCF 2 · 3 · 5 (which corresponds to 2, in expanded prime factorization as \(2^1 \cdot 3^1 \cdot 5^1\)) and LCM 2² · 3² · 5 (which corresponds to \( 2^2 \cdot 3^2 \cdot 5^1\)).

Thus, the correct choice is: GCF 2 · 3 · 5; LCM 2² · 3² · 5.