Can someone please answer this for me? I don’t really understand this part so well.

Answer:
2010
Step-by-step explanation:
N(t) = 113(0.973)^t
N(t) = 50
=> 113(0.973)^t = 50
0.973^t = 50/113
= 0.44
t = ^0.973 Log 0.44 = 30
the year = 1980 + 30 = 2010