Pls provide a clear explanation for further understanding. Thanks!

According to a recent research article, the irreversible decomposition of an organic compound (A) in a batch reactor can be represented by a mathematical model below: Ca = -4.0 x 10-5tr + 0.001t2 0.0097t + 0.0325 where t is the time (min) and Ca is the concentration in mol/dm. The experiment was conducted for four minutes, and data was collected at two minutes interval. Write the expression of the rate law for this process