Linear Relationships

Five short, interactive parts, then a real-world bonus. Do them in order. Each one has an animated lesson and practice. Part 5 mixes everything together, and Part 6 asks when a straight line is only a model.

1Slope from two points
Rise, run, and how steep a line is› 2Write the equation of a line
Find m and b, then build y = mx + b› 3Graph a line and tell its story
From an equation to a graph to real-world meaning› 4Proportional or just linear?
Compare relationships that pass through the origin with ones that don’t› 5Final review
Ten mixed questions, with a score for each skill› 6When the real world isn’t linear
A fitness tracker’s straight line versus how your body really burns calories›

Want to explore on your own? Try Line Lab, a sandbox with five stories you can adjust with sliders.