We can find the cost of the couch and coffee table as follow
Let the cost of the couch be C
Let the cost of the coffee table be T
First, we are told that they both cost $1290
Therefore, our first equation will be

Next, we are told the cost of the couch is twice that of the coffee table
so

Solving equations 1 and 2 simultaneously

Next, we will find the cost of the couch

The cost of the couch is $860
The cost of the coffee table is $430