Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

needhelpfastplease

  • one year 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
    • one year 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
    • one year 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
    • one year 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
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh so its C

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

    thanks!

  6. theEric
    • one year 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
    • one year 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
    • one year 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

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.