Algebra 2 help?

Question

A radio active isotope decays according to the exponential decay equation where t is in days.

Round to the thousandths place.

For the half life: The half life is the solution (t) of the equation : a2=ae−6.345t

Answer 1

a^2 = ae -6.345t

6.345t = ae - a^2

t = (ae-a^2)/6.345 days = half life