Question

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

Answer 1

Answer:

Step-by-step explanation:

7x11x13+13

13(7x11+1)

13(77+1)

13x13x3x2

since it is more than 2 factors

it is composite

7×6×5×4×3×2×1+5

5(7x6x4x3x2+1)

5(1008+1)

5(1009)

since it also has more than 2 factors

it is composite

Answer 2

Concept to be used here:

• Factorization ⇄ Distribution Law

The factorization of 7×11×13+13

• 13×(7×11+1)

The factorization of 7×6×5×4×3×2×1+5

• 5×(7×6×4×3×2×1+1)

The above are multiplication of two other numbers. Now since there are two factors besides 1, it is a composite number.

For your information,

Imagine if we had 10×(10+1).

It would become 10×10+10 because of the distribution law.

Now let us think of the opposite like if we had 10×10+10.

The opposite is factorization 10×(10+1).