Bob's Followers

Level pending

Bob had 10 followers on Brilliant the first week, 15 followers the second week, 25 followers the third week, and 45 followers the fourth week(now). How many followers will Bob have next week(the fifth week) if the number of followers Bob has is $$5+5(2^{x-1})$$?

("x" is the xth week, ex. 1st week x=1, 2nd week x=2, etc.)