Question

6. Explain why 7x11x 13+13 and 7x6x5 x 4x3x2x1 +5 are composite numbers.
please answer it !!​

Answer 1

Answer:

Yes they are

Step-by-step explanation:

This is because in the first case,

7 x 11 x 13 + 13

13 can be taken common

13 ( 7 x 11 + 1 )

This number is divisible by 13

Thus, it is composite

In the second case,

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

5 can be taken common

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

This number is divisible by 5

Thus, it is composite

In other cases, where you cannot factorise the number, you might have to just multiply and then add.

HOPE IT HELPS

Answer 2

Step-by-step explanation:

7×11×13+13 can be written as 13(7×11+1). We know that 13 is a prime number. By the Fundamental Theorem of Arithmetic it is a composite number.

7×6×5×4×3×2×1+5 can be written as 5(7×6×4×3×2×1+1). We know that 5 is a prime number.

By the Fundamental Theorem of Arithmetic it is a composite number.