Need an addition to code that subtracts (itself + 0.16) from x?

So I copied this from my code. How can I subtract (x + 0.16) from x and (y + 0.16) from y?

if(tileColors[x+y*levelWidth] == NcolWoodOneColor)
			{
				Instantiate(NcolWoodOneTile, new Vector2(x, y) * tileSideLength, Quaternion.identity);
			}
			if(tileColors[x+y*levelWidth] == NcolGrassOneColor)
			{
				Instantiate(NcolGrassOneTile, new Vector2(x, y) * tileSideLength, Quaternion.identity);

x-=(x+0.16)
y-=(y+0.16)

Im not sure if that is what you mean. I Do not fully understand the question.

Uh… as you state it

x= -0.16;
y= -0.16;

This is basic algebra…
x-(x+0.16) = x-x-0.16 = (x-x)-0.16 = (0) -0.16 = -0.16