The x-axis is the horizontal line in bold. It's basically asking what points in the form (x,y) are touching said line.
So we use our eyes and determine that the line intercepts the x-axis at -1 because that vertical bold line is the y-axis and it determines that the left side of the graph is negative and the right side is positive.
Since it is an x-intercpet, when the y-value is 0 the y-term in
