Question

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

Answer 1

Question :–

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

Solution :–

✏️ (7 × 11 × 13 + 13)

= (7 × 11 × 13 + 13 × 1)

= 13 (7 × 11 +1)

= 13 (77 + 1)

= 13 × 78

= 13 × 2 × 3 × 13

= 2¹ × 3¹ × 13²

It has more than two factors.

So, it is composite numbers.

✏️ 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5

= (7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 × 1)

= 5 (7 × 6 × 4 × 3 × 2 × 1 + 1)

= 5 (1,008 + 1)

= 5 × 1,009 × 1

It has more than two factors.

So, it is composite numbers.