# algebra - half lives

posted by
**Tritium** on
.

Half-life of tritium is 12.32 years.

Write decay equation as

N(t) = N(subzero)e^(-rt)

where t is the time in days, N(subzero) is the starting amt of tritium and N(t) is amt of tritium at time t.

don't know how to find -r.