Hello, thank you for taking the time to post your question!
The key on this type of question is to find a way to relate the two variables to one another based on the information given in the question. On this one we have
dist(motorcycle) = dist(car)
50t = 40(t + 3) because the motorcycle has been traveling at a speed of 50 miles per hour for “t” hours and the car has been traveling at a speed of 40 mph for “t + 3” hours
From there then you want to solve for the value of “t” algebraically
50t = 40t + 120
10t = 120
t = 12
that means that the motorcycle travels for 12 hours before overtaking the car.
Then to convert that over into a distance you can use the 50t expression
50 x 12 = 600 miles
So the two vehicles are 600 miles from the starting point when the motorcycle overtakes the car.
I hope that helps get you moving in the right direction! Feel free to reach out if you have any additional questions beyond that :)