the graph is decrasing, so the variable rate is negative (-2/3)
the rest was quite easy, you just take a look at where the graph cuts the y-axis and determine the rest from the rate of going up or down (increase/decrease)
The equation of the line is y = -2/3x - 13/3. The slope is negative since you go up 2 (pos) and then go to left 3 (neg). One negative number makes the whole slope negative.
