We have that
[tex]120x+(-2x)[/tex]
Remember that if you multiply plus and minus you get minus. Check out this table for sing multiplication
In other words, if you multiply two sings that are the same, you get a plus. Otherwise, you'll get a minus.
Therefore,
[tex]120x+(-2x)\rightarrow120x-2x\rightarrow118x[/tex]
The answer is 118x
