First you had to remove parenthesis first.

Multiply by the numbers.

Final answer 



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Answer:
1 represents the number of years passed.
step -by-step explanation:
The amount of a radioactive isotope decays in half every year. The amount of the isotope can be modeled by f(x) = 346 (1/2)x and f(1) = 173
Here 1 represents the number of years that passed.
So 1 represents the number of years.
Hope this will helpful.
Thank you.
Answer:
y=1/2x
Step-by-step explanation:
Look at the graph, all you need is the first point.
Y is at 4 and X is at 2. We can divide y/x to get 4/2=1/2x
Nice, already in vertex form
y=a(x-h)^2+k
(h,k) is vertex
therfor since (-3,6) is vertex
we are looking for something like
y=a(x-(-3))^2+6 simplified to
y=a(x+3)^2+6
A is ansre