Respuesta :

V/2 + 15.2 = -10.4
       - 15.2      - 15.2
             V/2 = -25.6
          2(V/2) =  2(-25.6) <
multiply by 2 so that the 2 in the denominator of the fraction will get canceled out and then you are left with just V. but you have to remember that whatever you do to one side of an equation you have to do to the other.
                 V = -51.2

hope this helps :)