The y intercept is 2, because that is the value of y when it crosses the y axis.
Since the line is pointing down, it has a negative slope, and since the y value goes down 2 for every 3 x values, the slope is -2/3. You should always right the slope in rise/run form, or change in y/change in x.
Finally, write the equation in the form of y=mx+b, where m is the slope and b is the y intercept. This means the equation of the line is y=-2/3x+2.