Answer:
It would be y = 2x+4
Explanation:
This is because Isabella has started with 4 baked pies and is gaining additional pies with in amounts of 2 pies.
With this, 4 would be by itself and 2 would be attached to the variable x for the unknown amount of additional pies.
Lastly, you would have this all equaling y, as y is the total amount of pies.