I need help with this！And also can they play 6 levels during their free trial?

How do you determine whether a relationship represented as as graph is linear or nonlinear

Suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12 y=7 when x=3

Will give brainliest for correct answer 8. use the distance time graph to answer these questions: a. what does the graph tell us about the velocity of the car? b. what is the average velocity of the car? (show work) c. is the velocity reflected in the graph positive or negative?d. is there any point on the graph where the car is not moving? how do we know?