I need the steps to this problem explained, please.

In the year 2000, the population of Virginia was about 7,400,000. Between the years 2000 and 2004, the population in Virginia grew at a rate of 5.4%. At this growth rate, the function f(x) = 7,400,000 (1.054)^x gives the population xyears after 2000.

In what year will the population reach 15,000,000?

In what year will the population reach 20,000,000?

Thanks.