Newbie looking or some help with add/substracting variables

Hello I'm new here but been  searching this forum and using autoit for quite sometime here.
excuse my noobness...

Here is an example of what I'm trying to do...
find a color, if it exist, store it's X and Y value.
Then click that location minus 50 on x and y values.

I can't figure how to add and substract to x and y

while 1
$Mine2Pixel = PixelSearch ( 75, 85, 799, 599, 0x181CEF)
if Not @error Then
  mousemove($mine2Pixel[0], $mine2Pixel[1])
  MouseClick("Left", $mine2Pixel[0], $mine2Pixel[1])
EndIf
WEnd

any ideas.. ?