<PRE><B>Question 831039</B>
1st hour = Car A travels 60 miles; Car B idle -- 60 miles apart
2nd hour = Car A travels 60 miles; Car B travels 75 miles -- 195 miles apart
3rd hour = Car A travels 60 miles; Car B travels 75 miles -- 330 miles apart
4th hour = Car A travels 60 miles; Car B travels 75 miles -- 465 miles apart
5th hour = Car A travels 60 miles; Car B travels 75 miles -- 600 miles apart
.
In algebraic form, let x be the number of hours
600 = 60 + (CarA+CarB)(x-1) [because the first hour is only 60]
Distribute
600 = 60 + 135x-135
Subtract 60 from each side
540 = 135x - 135
Add 135 to each side
675 = 135x
Divide by 135
5 = x


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