Question

25. 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.​

Answer 1

Answer:

13(7x11x1+1)

13(77+1)

13(78)

1014

now,1014=2x3x13x13

it has more than two prime no. therefore it is composite number