Respuesta :

His neighbors driveway is 17 m 37 cm, because 12.38 + 4.99 is 17.37 
Neuron
If you would like to know how long is neighbor's driveway, you can calculate this using the following step:

12 m 38 cm + 4 m 99 cm = 16 m 137 cm = 17 m 37 cm

Result: Neighbor's driveway is 17 m 37 cm long.