I have an equation, that I used in a software I made (Delphi). Now, I want to sort of "reverse" this equation. Y = 0-((( ClickedY * (1800 / PicHeight ))*2)-1800) X = (( ClickedX * (1800 / PicWidth ))*2)-1800 What does ClickedY = if you know Y and the PicHeight? what does ClickedX = if you know X and the PicWidth? Thanks in advance, hopefully, there is a mathematician that can solve this.