• (7 × 11 × 13 + 13)

Taking 13 as a common factor,

→ 13{(7 × 11) + 1}

= 13(77 + 1)

= 13(78)

The given numbers have 13 and 78 as a common factor other than 1 and the number itself

So, they are composite numbers.

• (7 × 6 × 5 × 4 × 3 × 2 × 1 + 5)

Taking 5 as a common factor,

→ 5{(7 × 6 × 5 × 4 × 3 × 2) + 1}

= 5(840 + 1)

= 5(841)

The given numbers have 5 and 841 as a common factor other than 1 and the number itself.

So, they are composite numbers

Know more :-

★ A composite number is a number which has common factors other than 1 and the number itself.

★ Composite numbers are not prime numbers.

★ For taking out the common factor, just take out the number which is added in the end.

Verified answer

Answer:

because they have more than one multiple