First understand that this is a linear graph. Find 2 points on the graph. We can use (0,1) and (3,-3).
Look at how much the x increases, in this case the x value increases by 0+3, so 3.
Then see how much the y value increases (make sure to evaluate them in the same order) 1 + (-3) = -2.
So you know that the y value decreases by 2 units for every 3 unit increase in x. Therefore the slope is y=(-2/3)x
Then figure out what you add to the end. The y intercept is (0,1), so add 1 to the end of y=(-2/3)x to move it up.
Your resulting eq is y=(-2/3)x+1
