Can someone explain to me how to do this question?
: )

5500 dollars is placed in an account with an annual interest rate of 6.5%. to the nearest tenth of a year, how long will it take for the account value to reach 19700 dollars?

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?