Respuesta :
treat i as a placeholder
get into standard form (a+bi)
distribute stuf and move
21-4i-16-7i+28i
21-16-4i-7i+28i
5+17i
get into standard form (a+bi)
distribute stuf and move
21-4i-16-7i+28i
21-16-4i-7i+28i
5+17i