I am not sure if I did this right. Just guessing.
algebra: please check - Ana, Thursday, June 10, 2010 at 10:10pm
The answer is -72.
You should have made the denominators alike so that you could subtract the fractions easier.
8p/24 - 9p/24 = 3
-p/24 = 3
-p/-1 = 72/-1
algebra: please check - Reiny, Thursday, June 10, 2010 at 11:31pm
Easier way ...
multiply each term by the LCD, which is 24, so
8p - 9p = 72
-p = 72
p = -72