Let the cost of the couch be x and the cost of the coffee table be y. If the cost of the couch is 2 times that of the coffee table, then it means the cost of the couch (which is x) is 2 times y. Simply put,
x = 2y.
If both items cost 1023, then it means;
x + y = 1023.
Therefore;
Therefore, the cost of the couch is 682, and the cost of the coffee table is 341.