B

was arrested

16/20

A?

Diện tích hình vuông:

20 x 20 = 400 (m²)

Diện tích cái ao hình tròn:

4,5 x 4,5 x 3,14 ≈ 64 (m²)

Diện tích còn lại:

400 - 64 = 336 (m²)

\(\Leftrightarrow3x=4\)

\(\Leftrightarrow x=\dfrac{4}{3}\)

Always should keep both hands on the handle bars.

Always wear a helmet when you ride a motorbike.

Give a signal before you turn left or right.

Use front and back lights at night.

Don't carry a passenger in front of you.

\(\dfrac{2}{3}+\dfrac{4}{5}\times\dfrac{5}{6}=\dfrac{2}{3}+\dfrac{2}{3}=\dfrac{4}{3}\)