Explain why 7 x 11 x 13 + 13 and 7 x 6 x 5 x 4 x 3 x 2 x 1 + 5 are composite numbers.

7 x 11 x 13 + 13 = 13 x (7 x 11 + 1) = 13 x 78

The given number has more than two factors.

Hence, it is a composite number.

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

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

= 5 x 1009 x 1

The given number has more than two factors.

Hence, it is a composite number.