Downhill Lines
Part of the Graphs & Systems section of Coddy's Algebra journey. Lesson 13 of 64.
A line with a negative slope goes down as you move right. Each step to the right takes you down instead of up. The line y = -2x + 4 has slope -2, so it goes down 2 for every step right. The minus sign tells you the line falls.
Slope -2 falls as fast as slope 2 climbs
The slope tells you two separate things. The size of the slope tells you how steep the line is. The sign tells you the direction. In the figure, the slopes 2 and -2 are equally steep, but one line goes up and the other goes down. A slope close to 0, like 1/10 or -1/10, gives a line that is nearly flat.
Challenge
EasyDraw the line with slope -2 that passes through (0, 5).
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Graphs & Systems
1The Coordinate Plane
Two Numbers, One PointThe Four QuadrantsPoints on the AxesMirror PointsRecap: The Plane4Slope-Intercept Form
y = mx + bThe Starting HeightWrite the EquationSolve for yDraw From Any FormRecap: y = mx + b7Parallel & Perpendicular
Same Slope, Never MeetThe Perpendicular SlopeA Right-Angle LineRecap: Two Relations2From Rule to Line
A Rule Makes PointsThe Points Line UpOn the Line or Not?Between the DotsRecap: Rule to Line