A compound event, I believe
Answer:
The side length of of the base of the tank is 15 inches.
Step-by-step explanation:
We are given the following in the question:
Cost of the tank and filter system = $280
Perimeter of tank base = 60 inches
The perimeter of tank is in the shape of square.
We have to find the side length of the base of the tank.
Perimeter of tank base = Perimeter of square =

Thus, the side length of of the base of the tank is 15 inches.
For this case, the first thing we should do is use the following equation:
x ^ 2 + x-30
Here, we substitute the value of x = 20
We have then:
(20) ^ 2 + (20) -30 = 390 m ^ 2
Answer:
the area of the land when the length of the dentist's office is 20 meters is:
390 m ^ 2