A 29 gram sample of a substance that's used to preserve fruits and vegetables has a k-value of 0.1359. Find the substance's half life in days. Round to nearest tenth

Okay well

a (t) = amount of substance remaining after t days

assuming exponential decay, a (t) = 29e^-0.1359t

now, find the half, set a (t) = half the original and solve for t

14.5=29e^-0.1359t

0.5=e^-0.1359t

In (0.5) = In (e^-0.1359t)

In (0.5) = - o. 1359t

t=in (0.5) / (-0.1359) = (aprox) 5.1 days