Ta có: 24n+1 + 34m+1
= 24n.2 + 34m.3
= (24)n.2 + (34)m.3
= (...6)n.2 + (...1)m.3
= (...6).2 + (...1).3
= (...2) + (...3)
= ...5
Vì ...5⋮5 nên 24n+1+34m+1⋮5
Vậy 24n+1+34m+1⋮5
Ta có: 24n+1 + 34m+1
= 24n.2 + 34m.3
= (24)n.2 + (34)m.3
= (...6)n.2 + (...1)m.3
= (...6).2 + (...1).3
= (...2) + (...3)
= ...5
Vì \(\overline{...5}⋮5\) nên \(2^{4n+1}+3^{4m+1}⋮5\)
Vậy \(2^{4n+1}+3^{4m+1}⋮5\)