a/ \(2^3.3:12+7^{10}:7^8=8.3:12+7^2=2+49=51\)

b/ 3*2 chia hết cho 2 => * \(\in\left\{0;1;2;3;4;5;6;7;8;9\right\}\)

c/ 14* chia hết cho 5  => * = 5 hoặc * = 0 .

14* chia hết cho 3  => 1 + 4 + * = 5 + * chia hết cho 3    => * = 1 hoặc * = 4 hoặc * = 7.

=1353

TÍCH NHA

\(A=2+2^2+2^3+...+2^9+2^{10}\)

\(=\left(2+2^2\right)+\left(2^3+2^4\right)+....+\left(2^9+2^{10}\right)\)

\(=2\left(1+2\right)+2^3\left(1+2\right)+...+2^9\left(1+2\right)\)

\(=2.3+2^3.3+...+2^9.3\)

\(=3\left(2+2^2+2^3+...+2^{10}\right)\)

\(\Rightarrow\)\(A\)chia hết cho \(3\)