Respuesta :

Answer:

A = 2000.

Step-by-step explanation:

A = kB^2 where k is a constant to be found, so substituting:

500 = k * 10^2

100k = 500

k = 5.

So we have

A =  5B^2

When B = 20:

A = 5 * 20^2

= 5 * 400

= 2000.