Sandy is observing the velocity of a runner at different times. after one hour, the velocity of the runner is 4 km/h. after two hours, the velocity of the runner is 2 km/h. part a: write an equation in two variables in the standard form that can be used to describe the velocity of the runner at different times. show your work and define the variables used. (5 points) part b: how can you graph the equations obtained in part a for the first 4 hours? (5 points)

The table and the graph below each show a different relationship between the same two variables, x and y: a table with two columns and 5 rows is shown. the column head for the left column is x, and the column head for the right column is y. the row entries in the table are 4,100 and 5,125 and 6,150 and 7,175. on the right of this table is a graph. the x-axis values are from 0 to 10 in increments of 2 for each grid line. the y-axis values on the graph are from 0 to 300 in increments of 60 for each grid line. a line passing through the ordered pairs 2, 60 and 4, 120 and 6, 180 and 8, 240 is drawn. how much more would the value of y be on the graph than its value in the table when x = 12? 20 30 60 70