Slope-intercept form, systems of equations & intersection — drag y-intercept dots
y = mx + b is slope-intercept form. The slope m is rise/run — how steep the line is. The y-intercept b is where the line crosses the y-axis. Two lines can be parallel (same slope, no intersection), perpendicular (slopes multiply to −1), or intersecting (different slopes, one solution). Toggle Shade Between to see the region between two lines. Drag the y-intercept dots on the canvas to move lines interactively!