Question

Find the prime factors of the following composite numbers using division method:
(a) 42
(b) 72
(c) 35
(e) 84
(d) 28
(1) 78
(g) 125
(h) 81​

Answer 1

Answer:

Step-by-step explanation

I: First we divide the number by the smallest prime number which divides the number exactly.

II: We divide the quotient again by the smallest or the next smallest prime number if it is not exactly divisible by the smallest prime number. We repeat the process again and again till the quotient becomes 1. Remember, we use only prime numbers to divide.

III: We multiply all the prime factors. Remember, the product is the number itself.

(a) 42           2 x 3 x 7

(b) 72           2 x 2 x 2 x 3 x 3

(c) 35           5 x 7

(e) 84           2 x 2 x 3 x 7

(d) 28           2 x 2 x 7

(1)  78           2 x 3 x 13

(g) 125         5 x 5 x 5

(h) 81​          3 x 3 x 3 x 3