\(2^{10}+2^{11}+2^{12}=2^{10}+2^{10}.2+2^{10}.2^2\)
\(=2^{10}.\left(1+2+2^2\right)=2^{10}.7\) chia hết cho 7
Vậy \(2^{10}+2^{11}+2^{12}\) chia hết cho 7
ta có : 2^10+2^11+2^12=2^10.(1+2+2^2)
= 2^10.(1+2+4)
= 2^10.7(*)
Thay (*) vào (2^10+2^11+2^12):7, ta được: 2^10.7:7=2^10(là số tự nhiên)
2^10+2^11+2^12
=2^10(1+2+2^2)
=2^10.7
vi 7 chia het cho 7 nen 7.2^10 cung chia het so 7 \(\Rightarrow\) 2^10+2^11+2^12 chia cho 7 la so tn