Which tiles should be added to the model below to make zero?O6 negative tilesO6 positive tilesO3 negative tiles and 3 positive tilesO6 negative tiles and 6 positive tiles

If the tiles have the same value then to make 0 you need:
3 negative tiles and 3 positive tiles.
Explanation:
If one tile has the value of 1 and you pot:
- 1 -1 - 1 + 1+ 1 + 1
it will be zero.