Carlos is five years older than twice his sister's age. Carlos is 13.
 Which equation and solution correctly identifies his sister's age?
 A.) 2 x + 5 = 13; x = 4
 B.) 2 x - 5 = 13; x = 9
 C.) 2 x - 5 = 13; x = 4
 D.) 2 x + 5 = 13; x = 9
 this is a multiple choice answer