Answer:

Step-by-step explanation:
The radius, r of the expanding circle of oil is modeled by the function:
, where s is time in seconds.
When s=5
Radius 
Area of a circle 
Therefore, the area of the oil spill when s=5 seconds

The area of the spill when s=5 seconds is 45pi square inches.
Answer:
4.5
Step-by-step explanation:
Using rounding I would change 198 to 200 and 727 to 730.
200 + 730 = 930. Some would change the 727 to 700 but I see no need to do that. My answer will be closer using 200+730.
You can also get the exact answer like this - when you raise 198 to 200, you raised it by 2 so to compensate, take 2 away from the other number and 727 becomes 725
I can do 200 + 725 = 925 in my head and that happens to be the exact answer.
Answer:
4
Step-by-step explanation:
f(3) = 12 - 3(3)
= 12 - 9
= 3
f(3) =3
f(3) + 1
= 3 + 1
= 4