Question 694645
There's a major problem here.


If car one goes x mph for t hours, then it will travel tx miles.


If car two goes x+20 mph for t hours, then it will travel (x+20)t = tx+20t miles


The difference between the two is 


(Car 2) - (Car 1)


(tx+20t) - (tx)


tx + 20t - tx


(tx - tx) + 20t


0tx + 20t


20t


So after t hours, they will be 20t miles apart. So in 10 hours, they are NOT 50 miles apart because when t = 10, 20t is 200. So they *should* be 200 miles apart in 10 hours.