In which of the following expressions, prime factorisation has been done?
(a) 24 = 2 × 3 × 4
(b) 56 = 7 × 2 × 2 × 2
(c) 70 = 2 × 5 × 7
(d) 54 = 2 × 3 × 9
Prime factorization is finding the factors of a number that are all prime.
(a) 24 = 2 × 3 × 4
As we can see in this factorization 4 is a composit number, so prime factorization has not been done.
(b) 56 = 7 × 2 × 2 × 2
Since all the factors are prime factors so, prime factorization has been done.
(c) 70 = 2 × 5 × 7
Since all the factors are prime factors so, prime factorization has been done.
(d) 54 = 2 × 3 × 9
As we can see in this factorization 9 is a composit number, so prime factorization has not been done.