Answer:
Train 1: 368 mph
Train 2: 358.1 mph
Explanation:
We can write 2 equations to represent this problem.
![x+y=726.1](https://img.qammunity.org/2021/formulas/mathematics/college/smvqagt7vrul5ukobf30mxrdvzvblqx1sn.png)
![x=9.9+y](https://img.qammunity.org/2021/formulas/mathematics/college/1m51mlpw8btq48vi7yl7kzm6yqeil2amfp.png)
The x represents the first train and the y represents the second train.
We can plug in x into the first equation.
![(9.9+y)+y=726.1](https://img.qammunity.org/2021/formulas/mathematics/college/k5wfbja4e7admlamw60cjin24nf0td5kfs.png)
![9.9+2y=726.1](https://img.qammunity.org/2021/formulas/mathematics/college/stzmwhlauq4pcnpzcbqzjel46rfll1pqnt.png)
![2y=716.2](https://img.qammunity.org/2021/formulas/mathematics/college/5kutzc1aeqvtgfipfv6sny93rws7sb1la6.png)
![y=358.1](https://img.qammunity.org/2021/formulas/mathematics/college/v91uwm9ir4zwnftyyzuhr03u5ffgmayjpl.png)
Now that we know our y, we can find our x.
![x=9.9+y](https://img.qammunity.org/2021/formulas/mathematics/college/1m51mlpw8btq48vi7yl7kzm6yqeil2amfp.png)
![x=9.9+358.1](https://img.qammunity.org/2021/formulas/mathematics/college/eh5zl98phhbfri2ab4c11xvnmzha0h06lp.png)
![x=368](https://img.qammunity.org/2021/formulas/mathematics/college/erof631mb8i6cr6inpn9qtkbvy7kfeo4rf.png)