More algebra 2 help? I'm really bad at these word problems...

Question

anonymous · Answer

The amount of radioactive isotope decays in half every 1 year. The amount of the isotope can be modeled by $$f(x)=346(\frac{ 1 }{ 2 })^x$$
and f(1)=173. What does the $$\frac{ 1 }{ 2 }$$ represent?

anonymous · Answer

A. The starting amount of the isotope
B. The amount of the isotope after 1 year
C. The rate the isotope decreases
D. The number of years that have passed

anonymous · Answer

Very similar to my last question

***[isuru]*** · Answer

hi,
  It's same as ur previous one .... It's represent the rate the isotope decays...
    it's C

anonymous · Answer

I thought so! I just needed reassurance :) thank you

***[isuru]*** · Answer

u r welcome!

anonymous · Answer

Help with another one like this? I think I have the answer but I want to be sure I am right...

anonymous · Answer

The population of a species of rabbit triples every year. This can be modeled by $$f(x)=4(3)^x$$ and $$f(5)=972$$ What does the 5 represent?
A. The starting population of the rabbits
B. The population of the rabbits after 5 years
C. The rat the population increases
D. The number of years that have passed

anonymous · Answer

I think the answer is B... @bhowl77 ?

***[isuru]*** · Answer

yes ... u r correct!!

anonymous · Answer

Awesome!

anonymous · Answer

Thankuuuuuuuu :DDDDDD