I take it you need to find the value of x, so it would be something like this if you needed to show how to work it out.
144=-12x-60
Add 60 to both sides to get rid of the -60
ie: 144+60 = -12x-60+60
204 = -12x
Divide both sides by the same factor:
204/-12 = -12x/-12
-17 = -12x/-12
Cancel terms that are in both the numerator and denominator
-17 = x
Solution: x = -17
*audible sound of brain deflation
...yea ok makes perfect sense thank you