Question

chứng minh rằng tổng 1.3.5.7.9.11 - 45 chia hết cho 9

Answer 1

\(=9\left(1\cdot3\cdot5\cdot7\cdot11-5\right)⋮9\)

Answer 2

=9(1⋅3⋅5⋅7⋅11−5)⋮9

Answer 3

=9(1⋅3⋅5⋅7⋅11−5)⋮9