\(B=2+2^2+2^3+2^4+...+2^{10}\)
\(=\left(2+2^2\right)+\left(2^3+2^4\right)+...+\left(2^9+2^{10}\right)\)
\(=2\left(1+2\right)+2^2\left(1+2\right)+...+2^9\left(1+2\right)\)
\(=3\left(2+2^2+...+2^9\right)⋮3\)
\(\Rightarrow B⋮3\)
..
\(B=2+2^2+2^3+...+2^{10}\)
=\(\left(2+2^2\right)+\left(2^3+2^4\right)+...+\left(2^9+2^{10}\right)\)
=\(2\left(1+2\right)+2^3\left(1+2\right)+...+2^9\left(1+2\right)\)
=\(2.3+2^3.3+2^5.3+2^7.3+2^9.3\)
=\(3\left(2+2^3+2^5+2^7+2^9\right)⋮3\)
Vậy \(B⋮3\)
\(B=2+2^2+2^3+...+2^{10}\)
\(B=\left(2+2^2\right)+\left(2^3+2^4\right)+...+\left(2^9+2^{10}\right)\)
\(B=2\left(1+2\right)+2^3\left(1+2\right)+...+2^9\left(1+2\right)\)
\(B=2\cdot3+2^3\cdot3+...+2^9\cdot3\)
\(B=3\left(2+2^3+...+2^9\right)\)
Vì \(3⋮3\Rightarrow3\left(2+2^3+...+2^9\right)⋮3\)
\(\Rightarrow B⋮3\)
Vậy ...
Có B=2+22+23+24+25+26+27+28+29+210
B=(2+22)+(23+24)+(25+26)+(27+28)+(29+210)
B=6+22(2+22)+24(2+22)+26(2+22)+28(2+22)
B=1.6+22.6+24.6+26.6+28.6
B=6(1+22+24+26+28) chia hết cho 6
2+2^2+2^3+2^4+..........+2^9+2^10
A=(2+2^2)+2^3+(2+2^2)+.........+2^10+(2+2^2)
A=2+2^2 +2+2^2 +2+2^2 +......+2+2^2
A=6+2^3 X 6+2^4x ..........x6+2^10
vì 6:3
vậy a:3
chúc bn hc tốt
nguoi ta hoi 3 tu nhien ra 6 bn oi~
thì chia hết cho 6 cũng chia hết cho 3 mà
haizz í mk là họ hỏi :3 ko:6
thì bạn có thể suy ra là nếu số này chia hết cho 6 thì nó cũng chia hết cho 3
OKEEEEEEEEEEEEEE