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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 6: CMR: Với mọi STN n thì ( 3^4n+1 ) + 2 chia hết cho 5

Toán Lớp 6: CMR: Với mọi STN n thì ( 3^4n+1 ) + 2 chia hết cho 5

Comments ( 2 )

  1. $3^{4n+1}+2$
    $= 3^{4n}.3+2$
    $= (3^4)^n.3+2$
    $= 81^n . 3 +2$
    $= \overline{…1}.3+2$
    $= \overline{…3}+2$
    $= \overline{…5} \;\vdots\; 5 \; \forall x\in \mathbb{N}$

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222-9+11+12:2*14+14 = ? ( )