I think the answer is irrational numbers, but i'm not sure
Formula for finding the area of a circle:

We need to radius but we only have the diameter.
Luckily for us, if you have the diameter, you have the radius.
Because the radius is the diameter over 2.
10 / 2 = 5
Plug in the values.
A = (3.14)5^2
A = (3.14)25
A = 78.5
So, the answer is 78.5.
Answer
N-9=-18
Move the -9 to -18 and add those cuz if there’s two negative u have to add
Add 9