prime factors. what are they? all composite numbers can be written as the product of prime numbers....
Post on 24-Dec-2015
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Prime Factors
What are they?
All composite numbers can be written as the product of prime numbers. This product is known as the prime factorisation of that number.
Example
The prime factorisation of 12 is 2x2x3
The prime factorisation of 42 is 2x3x7
How to find prime factors
To find the prime factorisation of 45, start by finding a factor of 45 that is also a prime number. The write 45 as a product.
45=5x9If the last number is not prime then repeat the process until 45 is written as a product of primes.
45=5x3x3
Example
Find the prime factorisation of 120.120 =2x60
=2x2x30=2x2x2x15=2x2x2x3x5
So 120=2x2x2x3x5.
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