-(x+49)+84=-103
=> -x-49=-103-84
=>-x-49=-187
=>-x=-187+49
=>-x=-138
=>x=138
vậy..............
-(x+49)=-103-84
-(x+49)=-187
187-x-49=0
X=138
-(x + 49) + 84 = -103
=> -x - 49 + 84 = -103
=> -x - 49 = -103 - 84
=> -x - 49 = -187
=> -x = -187 + 49
=> -x = -138
=> x = 138