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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
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

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theEric
 one year ago
Best ResponseYou've already chosen the best response.1This 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!

needhelpfastplease
 one year ago
Best ResponseYou've already chosen the best response.0im not really sure about this one i have no idea

theEric
 one year ago
Best ResponseYou've already chosen the best response.1I 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.

needhelpfastplease
 one year ago
Best ResponseYou've already chosen the best response.0oh so its C

theEric
 one year ago
Best ResponseYou've already chosen the best response.1You'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.

theEric
 one year ago
Best ResponseYou've already chosen the best response.1Going the other route, \(120\\=12\times10\\=3\times4\ \times\ 2\times5\\=3\times2\times2\ \times\ 2\times5\) Same thing, of course.. Same number! :)

theEric
 one year ago
Best ResponseYou've already chosen the best response.1I have to go. Take care! Good luck with whatever else you have to do!
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