Answer: -4
Step-by-step explanation: Don't knw if this will help but sometimes use a number line. Place the positive first then negative. search on google on how to do it.
Answer:
3 hours on the city roads and 4 hours on the other roads
Step-by-step explanation:
580 (total miles driven) - 400 (4 hours of driving 100km/h) = 180 (miles left)
180 (miles left to drive) / 60 (km/h) = 3 (hours driven at the speed of 60km/h)
I hope this helps :)