On February 21, a 61-year-old man who had gone to work in Italy disembarked in Brazil, more specifically in the city of São Paulo. After presenting the symptoms of the new coronavirus (fever, sore throat, runny nose and cough), he went to the hospital, where the first case of the disease in the country was confirmed through tests. From then on, we quickly had an explosion in the number of cases due to the exponential growth in the number of infected. Making a mathematical approximation through the disease progress function we were able to arrive at the following function representing the number of cases by the time in days of the first case. f(x) = Xi * R^t where : f(x) is the number of cases in a given time t Xi is the initial number of cases in a population R or Rt is the rate of spread, that is, to how many people an infected person transmits the disease on average t - Time measured in days. Calculate: If, when we reach 1,000,000 cases, our Rt rate drops to 0.90 ( Rt = 0.90 ) , how long would it take to zero the number of daily cases. (f(x) = 0 and Xi = 1,000,000 ).

uh here's the translation

i honestly don't know how i would do this one

it's way too wordy and it's confusing me.