Question

Answer 1

12. B

13. D

14. A

Answer 2

B

D

D

Answer 3

B-D-A

Answer 4

12.

\(12-3x\le0\)

\(\Leftrightarrow-3x\le-12\)

\(\Leftrightarrow x\ge4\)

13.△ABC∼△MNP \(\Rightarrow\dfrac{S_{ABC}}{S_{MNP}}=\left(\dfrac{AB}{MN}\right)^2=9\Rightarrow\dfrac{AB}{MN}=3\Rightarrow\dfrac{MN}{AB}=\dfrac{1}{3}\)

14.△ABC có AD phân giác \(\Rightarrow\dfrac{BD}{CD}=\dfrac{AB}{AC}\Rightarrow BD=\dfrac{AB}{AC}.CD=\dfrac{16}{24}.15=10\left(cm\right)\)