So, if I'm understanding you correctly, f(x)=x^2 divided by 3x+x, or
f(x) = (x^2)/(3x+x)
f(6) --> plug the 6 in to all values of x --> f(6) = (6^2)/(3×6 + 6) = 36/(18+6)
= 36/24 --> both are divisible by 12, so 36/12=3 and 24/12=2, now we have the reduced (simplified) answer:
f(6) = 3/2, or 1 1/2, or 1.5
If the diameter is 16, then the radius is 8.
A=(pi) r^2
8*8=64
64*3.14159265359=201.06
201.06 is your answer.
-TheOneandOnly003
Do 12-5 then 6.4 then 2.2 then whatever answer you get for 12-5 multiply it by the answer you get for 6.4 then subtract whatever answer you get for 2.2 hope this helps!