How do I find a1 for the geometric sequence down below
Sn = 1640, r = 3, n = 8

One integer is 8 times another. if the product is 72, then find the integers

Find the ratios of the corresponding sides

The equation represents the function f, and the graph represents the function g. f(x)=3(5/2)^x determine the relationship between the growth factors of f and g. a. the growth factor of g is twice the growth factor of f. b. the growth factor of f is twice the growth factor of g. c. the growth factor of f is 2.5 times the growth factor of g. d. the growth factor of f is the same as the growth factor of g.