SOLUTION: three hours after leaving her best friend's house , jessica's was 400 miles from home. five hours after she left her house she was 280 miles from her home. write a functions where

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Question 1033992: three hours after leaving her best friend's house , jessica's was 400 miles from home. five hours after she left her house she was 280 miles from her home. write a functions where x represents the number of hours spent driving and d(x) represents the distance from home
Answer by fractalier(6550)   (Show Source): You can put this solution on YOUR website!
Okay, like this...let's assume she travels at a constant rate...
Notice that after three hours, she is 400 miles from home, but after TWO hours more she is only 280 miles from home. That tells us that she travels at 120/2 = 60 miles per hour.
So THAT tells us that her friend's house was 3(60) = 180 miles plus the 400, or 580, miles from her house.
Now we have all we need...we write
d(x) = 580 - 60x

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