Rei is barricading a door to stop a horde of zombies. She stacks boxes of books on a table in front of the door. Each box weighs 30 kilograms, and the table with 8 boxes on top weighs a total of 310 kilograms.
The total weight W of the barricade in kilograms is a function of x, the number of boxes Rei stacks on the table.
Write the function's formula.
W =