Ta có: 210+211+212=210.1+210.2+210.22
=210.(1+2+22)=210. 7 \(⋮\)7
Vậy tổng (210+211+212) \(⋮\)7
( 2^10 + 2^11+2^12 ) = 2^10 x ( 2 + 2^2 )= 2^10 x 7 => chia het cho 7 :)
\(2^{10}+2^{11}+2^{12}=2^{10}\cdot\left(1+2+2^2\right)=2^{10}\cdot7⋮7\)
Vậy \(2^{10}+2^{11}+2^{12}⋮7\)
Ta có :
\(2^{10}+2^{11}+2^{12}\)
\(=2^{10}+2^{10}\times2+2^{10}\times2^2\)
\(=2^{10}\times\left(1+2+2^2\right)\)
\(=2^{10}\times7\)
Vậy \(2^{10}+2^{11}+2^{12}⋮7\)
_Chúc bạn học tốt_