Slope-intercept form: graph an equation

Graph lines efficiently from y = mx + b using intercept and slope moves.

Lesson 4

Concept

In y = mx + b, start at (0,b), then apply slope m as rise/run to generate more points.

Graph y = -1/2 x + 4.

In y = 3x - 2, y-intercept is:

-2

In y = -2x + 1, slope tells you to:

Up 2 right 1

Down 2 right 1

Right 2 up 1

Stay horizontal

These steps are out of order — can you fix them?

1.Plot (0,b)

2.Use m as rise/run

3.Identify b

4.Draw and verify line

Why is (0,b) always on the graph of y = mx + b?