I believe it is growth, decay would be the other way around.
Your answer is 4/5 because is see you put 8/10 which is correct but all you needed to do is simplify.
Answer:
Option A is your answer ☺️☺️
F=\dfrac{9}{5}C+32\\\\A.\\\dfrac{9}{5}C+32=F\ \ \ |-32\\\\\dfrac{9}{5}C=F-32\ \ \ |\cdot\dfrac{5}{9}\\\\C=\dfrac{5}{9}(F-32)
B.\\F=212\to C=\dfrac{5}{9}(212-32)=\dfrac{5}{9}\cdot180=100\\\\212^oF=100^oC
C.\\F=80\to C=\dfrac{5}{9}(80-32)=\dfrac{5}{9}\cdot48\approx26.7\\\\80^oF\approx26.7^oC
If the tax rate is 8%, we need to find 108% of the price, or 330 times 1.08, which is $356.4
