The difference between x and half of y

Every weekday, mr. jones bikes from his home to his job. sometimes he rides along two roads, the long route that is shown by the solid lines. other times, he takes the shortcut shown by the dashed line. how many fewer kilometers does mr. jones bike when he takes the shortcut instead of the long route?

Math i have no idea how to do a and b

The equation ip| = 2 represents the total number of points that can be earned or lost during one turn of a game. which best describes how many points can be earned or lost during one turn?