What do you mean? just the number 80?
Answer is D You'll do the diameter squared then you multiply by π
I think you can find it graphically by points through a table you create like:
let x = 0, and find the value of y
for example for the first equation when we let x = 0 you find y = 6 and be in the form of (0,6) then draw them or you can let x = -2 or -3 , etc as you like
to be more accurate you can find 3 pionts and start graphing them
these two equations are straight lines and they will intersect in a point
