A system of equations will have no solution if the lines are parallel to each other. Two lines are parallel when they have the same slope. All of your given equations are in the slope-intercept form. Recall the slope-intercept form is y=mx+b, where m is slope and b is the y-intercept. Therefore, the two equations would be Y = 3x + 1 and Y = 3x - 1, which both have a slope of m=3.
