The distance d between the train and the railroad marker can be expressed as:
d = 200 - 65h
where 200 represents the initial distance between the train and the marker, and 65h represents the distance the train has covered after h hours, assuming a constant speed of 65 miles per hour.
To find the time it will take for the distance between the train and the marker to be 4 miles apart, we can set d to 4 and solve for h:
4 = 200 - 65h
65h = 196
h = 196/65
So the equation to find the time it will take for the distance between the train and the railroad marker to be 4 miles apart is:
200 - 65h = 4
or
65h = 196
or
h = 196/65