7×11×13+13
=13(7×11+1)
=13(77+1)
=13×78
=13×2×3×13(by HCF)
=2×3×13^2
It is composite ( bcz it has more then 2 factors )
7×6×5×4×3×2×1+5
=5(7×6×4×3×2×1)
=5(42×24+1)
=5(1008+1)
=5×1009×1
It is also composite ( bcz it has also more then 2 factors )
Written on May 1, 2018, 9:44 a.m.