Question 1172663
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In 9 hours (9 = 11-2 hours), they covered  860 - 230 = 630 miles.


Hence, their average speed was  630/9 = 70 miles per hour.


It means that the linear equation relating D and t is  D = 1000 - 70t  miles.   <U>ANSWER</U>
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Solved.



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to the author/(the composer) &nbsp;of this problem &nbsp;&nbsp;--- &nbsp;a &nbsp;POST-SOLUTION &nbsp;note.


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    Actually, having only one piece of info

        "After driving a total of 2 hours, they are 860 miles away from their destination"

    is just ENOUGH to create such a function and to answer the problem's question.



    The other piece of info 

        "After driving a total of 11 hours, they are 230 miles away from their destination" 

    is just EXCESSIVE and UNNECASSARY . . . 
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