Question

Explain why 7×11×13+13 and 7×6×5×4×3×2×1+5 are compesite number.
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Answer 1

Solution:1st case

7*11*13+13 = 13(7*11+1) = 13*78 = 13*2*3*13

Since it has more than two prime factors, it is a composite number.

Similarly,

2nd case

7*6*5*4*3*2*1+5 = 5(7*6*4*3*2*1+1) = 5*1009

Since it has more than two prime factors, it is a composite number.

Answer 2

Answer:

Step-by-step explanation:

composite numbers are those numbers those are not prime(2,3,5,7,11,13....)

and composite numbers are 1,4,6,8,9,10,....

so as

7x11x13+13

91x11+13

1001+13

1014

s0 1014 is not  a prime number as it is divisible by 2 so it is a composite number

and7x6x5x4x3x2x1+5

720x7+5

5040+5

5045

hence 5045 is not a prime number as it is divisible by 5

so it is a composite number

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