Explain why 7×11×13× 13 and 7×6×5×4×3×2×1 5 are composite numbers
Answers!
7×11×13 13
=13(7×11 1)
=13(77 1)
=13×78
=13×13×3×2
since it has more than two factors (13,3,2,1,13)×78 I.e 1014. It is a composite number
Now,7×6×5×4×3×2×1 5
=5(7×6×5×4×3×2×1 1)
=5(1008 1)
=5(1009)
Since it has more than two factors (5,1009,1,5×1009 I.e 5045)
It is a composite number.
Comment
As in 7 x 11 x 13x 13 we can take 13 as common so we would left 13x(11 x7)which would be composite no as it would be divisible by 13 and products of 7 and 11
Do the same thing in other case
Answer the question...
7×11×13 13
=13(7×11 1)
=13(77 1)
=13×78
=13×13×3×2
since it has more than two factors (13,3,2,1,13)×78 I.e 1014. It is a composite number
Now,7×6×5×4×3×2×1 5
=5(7×6×5×4×3×2×1 1)
=5(1008 1)
=5(1009)
Since it has more than two factors (5,1009,1,5×1009 I.e 5045)
It is a composite number.
=13(7×11 1)
=13(77 1)
=13×78
=13×13×3×2
since it has more than two factors (13,3,2,1,13)×78 I.e 1014. It is a composite number
Now,7×6×5×4×3×2×1 5
=5(7×6×5×4×3×2×1 1)
=5(1008 1)
=5(1009)
Since it has more than two factors (5,1009,1,5×1009 I.e 5045)
It is a composite number.
Comment
As in 7 x 11 x 13x 13 we can take 13 as common so we would left 13x(11 x7)which would be composite no as it would be divisible by 13 and products of 7 and 11
Do the same thing in other case
Do the same thing in other case