Ta có:
A= 2+22+23+...+22010+22011+22012
A=(2+2^2)+(2^3+2^4)+...+(2^2009+2^2010)+(2^2011+2^2012)
A=(2+2^2)+2^2(2+2^2)+...+2^2008(2+2^2)+2^2010(2+2^2)
A=6+2^2x6 + .....+2^2008x6 + 2^2010x6
A=6x(1+2^2+...+2^2008+2^2010) chia hết cho 6
Vậy A chia hết cho 6
S =(2 + 22) + ( 23 + 24 ) +……..+ ( 22011 + 22012 )
= (2 + 22) +26(2 + 22) + ……….22010(2 + 22)
= 6 + 22.6 + ………22010.6
= 6 ( 1 + 22 + ……+ 22010 )
vậy chia hết cho 6
ta có A= 2 + 2.2 + 2^3 +.........+2^2012
=> A = 2 + 4+ 2^3 +.........+ 2^2012
=> A = 6 + 2^3 +...........+ 2^2012
vì 6 chia hết cho 6
=> A : hết cho 6 ( đpcm)
ta có: \(A=2^{ }+2^2+2^3+...+2^{2011}+2^{2012}\)
\(=\)\(\left(2+2^2\right)+\left(2^3+2^4\right)+...+\left(2^{2011}+2^{2012}\right)\)
\(=\)\(\left(2+2^2\right)+2^2\left(2+2^2\right)+...+2^{2010}\left(2+2^2\right)\)
\(=\)\(6+2^2.6+...+2^{2010}.6\)
\(=\)\(6.\left(2^2+2^4+...+2^{2010}\right)\)
do \(6⋮6\)
\(\Rightarrow\)\(2^2+2^4+...+2^{2010}⋮6\)
\(\Rightarrow\)\(6.\left(2^2+2^4+...+2^{2010}\right)⋮6\)
\(\Rightarrow\)\(A⋮6\)
vậy A chia hết cho 6
chuk bạn hok tốt