You can graph each line to see which one is horizontal since the y-axis is vertical. This would make the lines perpendicular since when a vertical and horizontal line meet, they form a 90-degree angle, which is by definition what perpendicular means.
Y - y1 = m(x - x1) slope(m) = 1...because a parallel line will have the same slope (1,-5)...x1 = 1 and y1 = -5 now we sub y - (-5) = 1(x - 1) = y + 5 = 1(x - 1) <== u could leave that first " one " out if u want...