I have been stuck on this problem for about an hour now. Could someone help explain how to get the answer to the second part of the question?

12. [1!2 Points] DETAILS PREVIOUS ANSWERS OBINPHYSS 1.P.015. .., MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A car is going 1? mls for 25 5. Draw an accurate graph showing the distance versus time for the car. d (m) d (In) 400 300 300 500 200 400 100 200 t (s) t [5) 5 10 15 20 25 O 5 10 15 20 25 d (m) 300 500 400 200 r (s) O 5 10 15 20 25 W What is the slope? x m Need Help