Question 1201192
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Matt took 7hrs to drive from Kingston to Montreal a total distance of 485 km. 
He drove most of the way at 100 km/h, but was slowed to 30 km/h during a trafic jam. 
How many hours he spend driving at each speed?
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<pre>
    t hours at the speed of 100 km/h, and 

(7-t) hours at the speed of 30 km/h.


Write the total distance equation

    100t + 30*(7-t) = 485  kilometers.


From this equation, find t.
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