Reversing equation

BlitzMax Forums/BlitzMax Programming/Reversing equation

So..

x = (a*30) - (b*30)
y = (a*15) + (b*15)

simplified :

x = (a - b) * 2
y = a + b

The result is :- Coming up After I've had a sleep!

Why can't you have a simple co-ordinate system?