Question

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

Answer 1

Any positive integer which has more than 2 factors is called composite number.
1)7×13×11+11
=11(7×13+1)
=11×92
=11×92×1(more than 2 factors)
=composite number
2)(7×6×5×4×3×2×1)+3
=3(7×6*5*4*2*1 +1)
=3×k×1 (more than 2 factors)
=composite number
Here k=7×6×5×4×2×1