Because it helps in reducing fractions to their simplest terms and finding the lowest common denominator when adding or subtracting fractions
It is called the prime factorisation (or prime decomposition) of the composite number.
22 x 7
78 = 2 * 3 * 13
46 = 23 x 2.
3 x 29 = 87
1450 as a product of primes = 2 * 5 * 5 * 29
To write a composite whole number as the product of its prime factors is to write its prime factorization.
It is 1*79 = 79.0 because 79 is a prime number
5x5x3
20 as a product of primes = 2 * 2 * 5
5*3
It is called the prime factorisation (or prime decomposition) of the composite number.
2 * 33 * 72
2*2*2*5*!
14 = 2 x 7
It is: 7 times 13 = 91
22 = 2 x 11