let 'x' be the number of miles Lemuel drive.
'n' be the number of days the truck is rented
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formulate the equation
since the rental for a day is 2000 then you'll have
2,000n --------2,000 multiplied by the number of days rented
........
since an additional payment of 150 will be charged for every mile then
150x --------for the payment as per mile is concerned
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you're given that Lemuel rented it for 2 days and that the bill is 5050
so you'll have it as
2,000n + 150x = 5050
where n=2
2000(2) + 150x = 5050
4,000 + 150x = 5050
150x = 5050 - 4000
150x = 1,050
x = 1,050/150
x = 7 miles