Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

needhelpfastplease

  • 2 years ago

What is the prime factorization of 126? A. 2^2 • 3 • 7 B. 2 • 3 • 7 C. 2 • 3^2 • 7 D. 2 • 3^2 • 72

  • This Question is Closed
  1. theEric
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    This is similar to the last multiple choice "what is the prime factorization of" problem. Eliminate the choices that have non prime numbers (like 72). Then you can just see which one works!

  2. needhelpfastplease
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    im not really sure about this one i have no idea

  3. theEric
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I divide by 2 whenever the number is even. So \(126\div2=63\). So \(126 = 2\times63\) 63 is \(7\times9\), I remember. So \(126 =2\times7\times9\) 7 is okay, it's a prime. 9 is not prime, so we check it out. \(9=3\times3\). So \(126=2\times7\times3\times3\) \(126=2\times7\times3\times3\) is the prime factorization.

  4. needhelpfastplease
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh so its C

  5. needhelpfastplease
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks!

  6. theEric
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You're welcome! If you want to just go through any number's prime factorization, divide by 2 when you can if you can't, divide by 3 if you can't, divide by 5 if you can't, divide by 7 if you can't, divide by 11 and if you can't divide by other primes. Or, if you see a number like \(120\), go straight for the common sense \(12\times 10\) so you can get right to the lower numbers! But going through the primes is good, too. \(120=2\times 60\) Side note: 60 is easy, too... \(120=2\times2\times30\) \(120=2\times2\times2\times15\) 2 doesn't work. \(120=2\times2\times2\times3\times5\) All primes.

  7. theEric
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Going the other route, \(120\\=12\times10\\=3\times4\ \times\ 2\times5\\=3\times2\times2\ \times\ 2\times5\) Same thing, of course.. Same number! :)

  8. theEric
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I have to go. Take care! Good luck with whatever else you have to do!

  9. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy