Formula for coordinates

[Sumomo]

Hehe i hobe someone is good in math.
I think i have a korrekt formula, but i dont get the right result. :grr:
So can someone please help me?
x = 128 + ((position- coordinate) / Size) this is my formula
now i need the formula for
position= :blink:
Can someone help me?

 

[Sumomo]

I got it=) xD