Question

Chứng minh rằng 7⁶+7⁵-7⁴ chia hết cho 55

Answer 1

\(7^6+7^5-7^4=7^4.\left(7^2+7-1\right)=7^4.55\)

\(\Rightarrow7^6+7^5-7^4⋮55\)

Chúc em học tốt!!!

Answer 2

___________________________Hướng dẫn_____________________________________

\(7^6+7^5-7^4=7^4.49+7^4.7-7^4=7^4\left(49+7-1\right)=7^4.55⋮55\left(đpcm\right)\)