Since the lines are parallel and you know the slope of [tex] y_{1} [/tex] is -2, you know the slope of line [tex] y_{2} [/tex] will also be -2. You can see on the coordinate grid that line [tex] y_{2} [/tex] crosses the y-axis at -1. When you piece all of these facts together into slope-intercept form you get [tex] y_{2} [/tex] = -2x - 1.
