Question

Explain why 7.13.11+11 and (7.6.5.4.3.2.1)+3 are composite numbers

Answer 1

Answer:

Step-by-step explanation:

7 x 13 x 11 + 11

= 11 ( 7 x 13 + 1 )

= 11 ( 92 )

= 11 x  ( 2 x 2 x 23 )

Since it has more than two factors (11 x 2 x 2 x 23  = 1012) It is a composite number.

(7 x 6 x 5 x 4 x 3 x 2 x 1 ) + 3

3 ( 7 x 6 x 5 x 4 x 1 x 2 x 1 ) + 1

3 (1680 + 1)

3 (1681)

Since it has more than two factors ( 3 , 1681 ,1 , 3 x 1681 = 5043)

It is a composite number