<image>As shown in the figure, a car and a bus depart simultaneously from Dezhou and Tai'an heading towards Jinan. After 2 hours, they are still n kilometers apart.

(1) Derive an expression with variables to represent the distance between Dezhou and Tai'an.
(2) When \( a = 60 \) and \( n = 10 \), what is the distance between Dezhou and Tai'an in kilometers?