We can determine from their equations whether two lines are parallel by comparing their slopes. If the slopes are the same and the y-intercepts are different, the lines are parallel. If the slopes are different, the lines are not parallel. Unlike parallel lines, perpendicular lines do intersect. So if the slopes have reciprocals, they are perpendicular. Otherwise, they are neither.
How I got my answer is that you write the numbers and the difference of the each 2 numbers. When you see the pattern is 5, 10, 20, and it might as well be 25 because you are going to start all over with the pattern