A certain arithmetic sequence has the following for the nth term an= 12 + (n-1)(5) State whether its a, b, c, or d please.

Problem number 26 of the rhind papyrus says: find a quantity such that when it is added to of itself the result is a 15. the modern day equation that models this problem is x + x = 15. what is the solution to the equation? x = 10 x = 12 x = 15 x = 30