jen can run at 7.5 m/s and mary at 8.0 m/s. on a race track jen is given a 25 m head start, and the race eds in a tie. how long is the track?

let x = distance run by jen.
x + 25 = distance run by mary.

time jen = d/r = x/7.5
time mary = d/r = (x+25)/8

Since they arrived at the finish line at the same time, then the times for the two are equal. Set them equal and solve for x, the distance run by jen which is the full distance of the track. Post your work if you get stuck and need further assistance. Check my thinking. Check my work carefully.