Bike trip: 30 miles in 2 hours
Maya bikes at a steady pace. Let's see how her distance grows with time.
We'll put hours along the bottom and miles up the side.
After two hours, she's gone thirty miles. After four hours, sixty miles.
The points line up perfectly — it's a proportional relationship.
To find the slope, we pick two points: two comma thirty, and four comma sixty.
Moving right from the first point, time changes by two hours. We call this the run.
Moving up to the second point, distance changes by thirty miles. That's the rise.
Slope is rise over run — so thirty divided by two.
Thirty divided by two is fifteen.
Fifteen miles per hour — that's Maya's speed, the unit rate!
The slope of the line IS the unit rate. Both equal fifteen miles per hour.