What are the coordinates of the y-intercept of the graph of:?

Presentation is unclear due to lack of brackets.
As give MUST be read as :-
f (x) = y = [ 2 x 3^(x) ] - 1
f (0) = y = 5
Point (0,5)
However could it be that you actually mean :-
f (x) = y = 2 [ 3^(x - 1) ]
f (0) = y = 2/3
Point (0,2/3)

PS
What DID you mean?

However could it be that you actually mean :-
y =

To find the y-intercept, set x=0
f(x) = (2) 3^(x-1)
x=0
f(x) = 2^(3)^(-1) = 2/3
(0,2/3) is the y-intercept