Mr. Cooper determined functions to represent his distance traveled in miles, d, in terms of the number of hours. 1, of driving on two types of highways. He found that on a state highway the function was d = 45t, and on a U. S. highway, the function was d = 601.
If Mr. Cooper drove for 1.5 hours on each type of highway, how much farther did he drive on the U. S. highway than on the state highway?

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miles