HELP! I really want to lose 25 pounds fast! Like in 6-7 weeks! Help me!
And I'm 14 year old girl who is 5ft 4in and weighs 140 pounds!

There is no way to lose 25 pounds in 6 weeks, ( not healthy) Perhaps over 3 or 4 months.

You good balanced meals and exercise. Plus unless you are of a really small frame, most body height and wieght charts would not want you at 115 pounds ,

You would need to starve yourself to lose that much in such a short period. But even if you could, you really shouldn't. Rapid weight loss is neither maintainable or healthy. See here for more How do I achieve rapid weight loss (http://www.womenrepublic.co.uk/diet_fitness/rapid/) . The only proper way to lose weight is through a healthy balanced diet with regular exercise.

The secret of losing weight is to loose calories.
I work out on stationary bicycle and burn 900+ calories in 45 minutes.
I have lost 12 kgs in 50 days with cycling and a bit of dieting.