According to the information given in the exercise, the following expression represents the area of the rectangular garden:

And the following expression represents the combined area of the walkway around the rectangular garden and the area of the garden:

You can identify that the word "combined" indicates that that expression was obtained by adding both areas.
Knowing the above, you can set up the following equation:

Where "A" is the area of the walkway around the rectangular garden.
Solving for "A", you get the following expression:

The answer is:
We use a system of equations to solve this. Since tri city sells 4 times it becomes 4x and solly company is x. Then we do 4x-x=96. 3x=96. x=32. We are not finished yet. We still have to multiply x by 4. x=128. Tri City sold 128 dishwashers.
Answer: (5, -6) and 3
Step-by-step explanation: