Answer:
7g-2e
Explanation:
What helps me with these equations is if you add parentheses to each section so...
(+12g) (-8e) (-5g) (+6e)
Now find the number that have the same lettered variables
+12g -5g put these together and you get +7g
-8e+6e put these together and you get -2e
then put it back in the equation --> 7g-2e