Respuesta :

Answer:

900m

Step-by-step explanation:

All you have to do is find the difference between the two measurements

500 - (-400)

Then, two negatives create a positive:

500 + 400

= 900

Answer:

900 m

Step-by-step explanation:

500m is above zero

-400 m is below zero

500 steps to 0 and then 400 steps to -400

500+400 = 900

500 - (-400) = 900 m