10-5 Writing Slope-Intercept Equations of Lines and 10-6 Parallel and Perpendicular Lines – We learned to write a linear equation in slope-intercept form given the slope of a line and the coordinates of a point on the line. Then we practiced writing a linear equation in slope-intercept form given the coordinates of two points on a line. Next we practiced writing an equation of a line that passes through a given point and is parallel or perpendicular to the graph of a given equation.