Respuesta :

tramserran

Answer: 1st train = 364 mph, 2nd train = 356.2


Step-by-step explanation:

Train 1: x + 7.8

Train 2: x

Train 1 + Train 2 = Sum

x + 7.8 +     x      = 720.2

           7.8 + 2x = 720.2

                    2x = 712.4

                      x = 356.2


Train 1: x + 7.8

 = 356.2 + 7.8

 = 364