A radioactive isotope decays at the rate indicated by the exponential
1500
function A(t) = 800
where t is the time in years and
the amount of the isotope, in grams, remaining.
What will the mass of the isotope be after 4500 years?

What is the sum of the geometric series in which a1 = 7, r = 3, and an = 1,701? hint: cap s sub n equals start fraction a sub one left parenthesis one minus r to the power of n end power right parenthesis over one minus r end fraction comma r ≠ 1, where a1 is the first term and r is the common ratio