This is the concept of algebra, suppose the initial number was x, and the new number is 2x. The constant rate of growth is r and time is D, the function representing growth will be given by:
2x=x(r)D
from our choices the equations that represents the information above will be:
7.830=3.915(1.106)D
and
7.830=3.915(2)D
this is because from both equations we see the initial number was 3.915 and doubled to 7.830
