<PRE><B>Question 553372</B>
Two trains leave Sacramemto at the same time. One travel East at 40mph.
 The other traveled West at 60mph.
Write amd solve a system of linear equations that can be used to determine when the trains are 280 miles apart.
:
Let t = travel time required for them to be 280 mi apart 
:
write a distance equation; dist = speed * time
:
train 1 dist + train 2 dist = 280 mi
40t + 60t = 280
100t = 280
t = 280/100
t = 2.8 hrs, they will be 280 mi apart
:
:
Check this by finding the distance that each traveled
2.8*40 = 112 mi
2.8*60 = 168
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total:  280 mi
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