Question

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

Answer 1

What is a composite number?

A number which has factors or multiplies other than the number itself and one are known as composite numbers

Implies,

Composite numbers should have more than 2 Factors

1. 7×11×13+13

Taking 13 as common,

=13(7×11+1)

=13×78

=13×13×6

=2×3×13²

Thus,the product of above numbers is composite

2. 7×5×4×3×2×1+5

Taking 5 common,

=5(7×1×4×3×2×1+1)

=5×169

=5×13²

Hence,the product of given numbers is a composite number

Answer 2

Answer:

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

Step-by-step explanation:

Composite number:

A number which has more than two factors is called composite number.

Now,

i) 7×11×13+13

= 13(7×11+1)

= 13(77+1)

= 13×78

= 13×78×1 [more than two factors]

= composite number

ii) 7×6×5×4×3×2×1+5

=5(7×6×4×3×2×1+1)

= 5(1008+1)

= 5×1009

= 5×1009×1[more than two factors]

= composite number

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