Question

explain why 7*11*13+13 and 7*6*5*4*3*2*1+5 are composite numbers​

Answer 1

7*11*13+13=1014

7*6*5*4*3*2*1+5=5045

These numbers are expressed as a product of primes. Therefore this is a composite number.

Answer 2

Question :-

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

Solution :-

Given numbers are

7 × 11 × 13 + 13 and

7 × 6 × 5 × 4 × 3 × 2 × 1 + 5

➡ 13(7 × 11 + 1) and

5(7 × 6 × 4 × 3 × 2 × 1 + 1)

➡ 13 K and 5 L, where K = 78 and

L = 7 × 6 × 4 × 3 × 2 × 1 + 1 = 1009

As the given numbers can be written as product of two numbers, they are composite.