20+12x+x^2=2y. Find the vertex form

Ineed someone to me answer my question i have to have this done and knocked out

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.

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.