Dấu hiệu chia hết cho cả 3 và 9 !!

A. $\left\{9, 27, 21\right\}$

B. $\left\{9, 18, 27\right\}$

C. $\left\{11, 22, 33\right\}$

D. $\left\{9, 17, 227\right\}$

A. 9

B. 10

C. 11

D. 12

A. 4319

B. 4321

C. 4320

D. 4322

A. $x\in \left\{27\right\}$

B. $x\in \left\{28\right\}$

C. $x\in \left\{21\right\}$

D. $x\in \left\{30\right\}$

A. $x\in \left\{23, 24, 25, 26, 27, 28, 29\right\}$

B. $x\in \left\{21,22, 23, 24, 25, 26, 29\right\}$

C. $x\in \left\{21, 24\right\}$

D. $x\in \left\{21, 22, 23, 24, 25, 26, 27, 28, 29\right\}$

A. x=22

B. x=25

C. x=27

D. Đáp án khác

A. $x\in \left\{21, 22, 23, 24, 25, 26\right\}$

B. $x\in \left\{22, 23, 24, 25, 26, 27, 28\right\}$

C. $x\in \left\{21, 22, 23, 24, 25, 26, 27\right\}$

D. $x\in \left\{21, 23, 24, 25, 26, 27\right\}$