Assume the half-life of a substance is 31 days and the initial amount is 172.799999999996 grams.

(a) Fill in the right hand side of the following equation which expresses the amount A
of the substance as a function of time t
(the coefficient of t in the exponent should have at least five decimal places):

A = 172.799999999996 × 0.5^(t/31)