Aleksandra started studying how the number of branches on her tree grows over time. Every 1.51.51, point, 5 years, the number of branches increases by an addition of \dfrac{2}{7} 7 2 start fraction, 2, divided by, 7, end fraction of the total number of branches. The number of branches can be modeled by a function, NNN, which depends on the amount of time, ttt (in years). When Aleksandra began the study, her tree had 525252 branches. Write a function that models the number of branches ttt years since Aleksandra began studying her tree.