Question

[Võ Ngọc Phương Uyên]

CM:

\(7^6+7^5-7^4\) Chia hết cho 11

\(24^{54}\cdot;54^{24}\cdot2^{10}\) Chia hết cho \(72^{63}\)

Answer 1

[✓ ℍɠŞ_ŦƦùM $₦G ✓]

\(7^6+7^5-7^4=7^4\left(49+7-1\right)=7^4.55\)chia hết cho 11

=>ĐPCM

\(24^{54}.54^{24}.2^{10}=8^{54}.3^{54}.27^{24}.2^{24}.2^{10}=2^{162}.3^{54}.3^{72}.2^{34}\)

\(=2^{196}.3^{126}=2^{189}.2^7.9^{63}=8^{63}.9^{63}.2^7=72^{63}.2^7\)chia hết cho 72⁶³

=>đpcm

Answer 2

[Nguyễn Đan Quỳnh]

7⁶+7⁵-7⁴=132055 chia hết cho 11