Answer:
The distance each bus travels is given as d=tr where
- d is distance bus travels
- t is a time bus travels
- r is the speed of the bus
:
Distance first bus travels for 4 hours is d1=4r.
Distance other bus travels for 4 hours is d2=4(r+12).
:
The total distance between them is 480 miles and since they go in opposite directions this distance is the sum of distances each bus travels.
:
d1+d2=480
4r+4(r+12)=480
4r+4r+48=480
8r+48=480
8r=432
r=432/8
r=54 mph, this is a speed of the first bus
:
r+12=66 mph, this is the speed of the second bus
Hope this helps you!!!! :D