Look at the balance sheet below. On the line, explain what a positive and negative number means in this situation. Make sure to write TWO sentences: one for what any positive number IN THIS PROBLEM means and one for any negative number. *

X is 12

Its kinda hard to explain but let me put it this way
If you can translate each of the fractions to have the same denomenator then it makes things a lot easier.

First you translate the equation into 9/12x - 4/12x + 10/12x = 12/12x + 3

Then subtract 12/12x from both sides to get 

9/12x - 4/12x + 10/12x - 12/12x = 3

Subtract 9/12x -4/12x = 5/12x

Then add 5/12x to 10/12x = 15/12x 

Then subtract 15/12x - 12/12x = 3/12x 

So you should get 3/12x = 3

which is 1/4x = 3 

Multiply both sides by 4 and you get 

x = 12