Respuesta :

faizu
-124=-7(2n+4)+2n
=> 
-7(2n+4)+2n = -124 .. ( switch sides )
=> -14n - 28 + 2n = -124
=> -12n = -124 + 28 
=> -12n = -96
=> n = -96/-12
=> n = 8 ...

Hope it helps !!!