The slope is always the rise of the graph over the run of the graph. The x-intercept is what x is when the line touches the x-axis. the y-intercept is what y is when the line touches the y-axis.
Therefore:
Graph 1: slope=0 because it rises 0 per one unit it runs. x-intercept does not exist because the line will never touch the x-axis. y-intercept is at (0, -1)
Graph 2: slope=-1 because the graph falls one unit per unit it runs. x-intercept and y-intercept are both at (0, 0).
Graph 3: slope=1 because it rises one per unit traveled to the right. x-intercept is at (-2, 0) and y-intercept is at (0, 2).
Hope I helped!