Let x be your initial score.
You double it, so your score becomes 2x.
You lose 75 points, so your score becomes 2x-75
This equals -25, so we have the following equation:
[tex]2x-75=-25 \iff 2x=50 \iff x=25[/tex]
In fact, things went like this:
You start with 25 points
You double your score, and you have 50 points
You lose 75 points and end with -25 points.
