Two lines are parallel if the have the same slope. Example 1: Find the slope of the line parallel to the line 4x \u2013 5y = 12. To find the slope of this line we need to get the line into slope-intercept form (y = mx + b), which means we need to solve for y: The slope of the line 4x \u2013 5y = 12 is m = 4/5.
