SOLUTION: A jet flies from Toronto to Rome. Its flight can be modeled by the equation d=7200-800t where d is the distance, in kilometers, from Rome and t is the time travelled, in hours. G

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: A jet flies from Toronto to Rome. Its flight can be modeled by the equation d=7200-800t where d is the distance, in kilometers, from Rome and t is the time travelled, in hours. G      Log On

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Question 447118: A jet flies from Toronto to Rome. Its flight can be modeled by the equation d=7200-800t where d is the distance, in kilometers, from Rome and t is the time travelled, in hours. Graph the linear relation and how long does it take to fly 4000km. We are unable to solve this problem. Can you assist?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+d+=+7200+-+800t+
The graph is:
+graph%28+400%2C+400%2C+-5%2C+10%2C+-1000%2C+10000%2C+7200+-+800x%29+
The plane begins its flight at Toronto at t+=+0
Putting this into the equation:
+d+=+7200+-+800%2A0+
It has 7200 km to fly to reach Rome
If it flies 4000 km, It will have +7200+-+4000+=+3200+
km to go to reach Rome
Putting this into equation:
+3200+=+7200+-+800t+
+-800t+=+-4000+
+t+=+5+
After traveling for 5 hours it will be 3200 km from Rome
and it will have covered 4000 km
This agrees with the graph
Notice that when d+=+0, it has reached Rome
+0+=+7200+-+800t+
+800t+=+7200+
+t+=+9+
This says the whole trip takes 9 hrs