Question 569540
I find that a minus sign is easier to deal with if I see it as part of the number that follows it. If I do not see a number, the number is an invisible 1.  So for  {{{x-5}}}, I see {{{x + (-5)}}}.  And for {{{8-x}}}, I see {{{8 + (-1)x}}}.  
For the problem above, I prefer to believe that I am seeing
{{{(5x+4)+(-1)(6x+2)}}}
I do not write it that way, but I see it that way in my mind, and that helps me keep the signs straight.
{{{(5x+4)+(-1)(6x+2)=5x+4-6x-2=-x+2}}}
Otherwise, you have to remember (and hopefully justify to yourself) that to eliminate a set of brackets right after a minus sign, you also have to reverse all the signs inside the brackets, so that -(6x+2)=-(+6x+2) turns into {{{-6x-2}}}.